[update] descriptive image alt text for SEO

- replace filename-only/generic alt (Menubar, Toolbar, Classic mode,
  RichText initialization, etc.) with meaningful descriptions on docs screenshots
- localize alt text per locale (en, ru, de, ko, zh) to match each translation
- guide screenshots get framework-specific alt (React/Angular/Vue/Svelte)

Author: serhiipylypchuk1991

docs/guides/configuration.md

@@ -25,13 +25,13 @@ RichText supports two layout modes for the editing area:
 - `"classic"` — the edit area fills the entire page
 
 <div className="img_border">
-![Classic mode](/img/richtext/classic_mode.png)
+![DHTMLX RichText editor in classic layout mode](/img/richtext/classic_mode.png)
 </div>
 
 - `"document"` — the edit area mimics a document page
 
 <div className="img_border">
-![Document mode](/img/richtext/document_mode.png)
+![DHTMLX RichText editor in document layout mode](/img/richtext/document_mode.png)
 </div>
 
 Set the [`layoutMode`](api/config/layout-mode.md) property during initialization to choose the mode:

docs/guides/integration_with_angular.md

@@ -294,7 +294,7 @@ platformBrowserDynamic()
 Start the app to see RichText render with data on the page.
 
 <div className="img_border">
-![RichText initialization](/img/trial_richtext.png)
+![DHTMLX RichText rendered in an Angular application with sample content](/img/trial_richtext.png)
 </div>
 
 You now have a working RichText integration in Angular. Customize the code to fit your needs. A complete example is available on [GitHub](https://github.com/DHTMLX/angular-richtext-demo).

docs/guides/integration_with_react.md

@@ -247,7 +247,7 @@ useEffect(() => {
 Start the app to see RichText render with data on the page.
 
 <div className="img_border">
-![RichText initialization](/img/trial_richtext.png)
+![DHTMLX RichText rendered in a React application with sample content](/img/trial_richtext.png)
 </div>
 
 You now have a working RichText integration in React. Customize the code to fit your needs. A complete example is available on [GitHub](https://github.com/DHTMLX/react-richtext-demo).

docs/guides/integration_with_svelte.md

@@ -261,7 +261,7 @@ onDestroy(() => {
 Start the app to see RichText render with data on the page.
 
 <div className="img_border">
-![RichText initialization](/img/trial_richtext.png)
+![DHTMLX RichText rendered in a Svelte application with sample content](/img/trial_richtext.png)
 </div>
 
 You now have a working RichText integration in Svelte. Customize the code to fit your needs. A complete example is available on [GitHub](https://github.com/DHTMLX/svelte-richtext-demo).

docs/guides/integration_with_vue.md

@@ -271,7 +271,7 @@ export default {
 Start the app to see RichText render with data on the page.
 
 <div className="img_border">
-![RichText initialization](/img/trial_richtext.png)
+![DHTMLX RichText rendered in a Vue application with sample content](/img/trial_richtext.png)
 </div>
 
 You now have a working RichText integration in Vue. Customize the code to fit your needs. A complete example is available on [GitHub](https://github.com/DHTMLX/vue-richtext-demo).

docs/how_to_start.md

@@ -9,7 +9,7 @@ description: You can explore how to start working with DHTMLX RichText in the do
 This clear and comprehensive tutorial will guide your through the steps you need to take in order to get a fully functional RichText on a page.
 
 <div className="img_border">
-![DHTMLX RichText Classic Mode](/img/richtext/classic_mode.png)
+![DHTMLX RichText WYSIWYG editor running on a web page](/img/richtext/classic_mode.png)
 </div>
 
 ## Step 1. Including source files

docs/index.md

@@ -36,7 +36,7 @@ The RichText menubar provides access to editing actions such as creating a new d
 Use the [`menubar`](api/config/menubar.md) property to toggle its visibility. While the menubar can be enabled or disabled, its contents are not configurable at this time.
 
 <div className="img_border">
-![Menubar](/img/richtext/menubar.png)
+![DHTMLX RichText menubar with document and file actions](/img/richtext/menubar.png)
 </div>
 
 ### Toolbar
@@ -46,7 +46,7 @@ The RichText toolbar provides quick access to text formatting and structural edi
 The [`toolbar`](api/config/toolbar.md) property allows you to fully customize the toolbar’s content and layout. You can enable or disable toolbar, rearrange default controls, or define a fully custom toolbar using an array of predefined button identifiers and custom button objects.
 
 <div className="img_border">
-![Toolbar](/img/richtext/toolbar.png)
+![DHTMLX RichText toolbar with text formatting controls](/img/richtext/toolbar.png)
 </div>
 
 ### Editor
@@ -60,13 +60,13 @@ DHTMLX RichText can work with content in "classic" and "document" modes. You can
 - `"classic"`
 
 <div className="img_border">
-![Classic mode](/img/richtext/classic_mode.png)
+![DHTMLX RichText editor in classic layout mode](/img/richtext/classic_mode.png)
 </div>
 
 - `"document"`
 
 <div className="img_border">
-![Document mode](/img/richtext/document_mode.png)
+![DHTMLX RichText editor in document layout mode](/img/richtext/document_mode.png)
 </div>
 
 ## Supported formats
@@ -76,13 +76,13 @@ The RichText editor supports [parsing](api/methods/set-value.md) and [serializat
 #### HTML format
 
 <div className="img_border">
-![HTML format](/img/richtext/html_format.png)
+![DHTMLX RichText content serialized to HTML format](/img/richtext/html_format.png)
 </div>
 
 #### Text format
 
 <div className="img_border">
-![Text format](/img/richtext/text_format.png)
+![DHTMLX RichText content serialized to plain text format](/img/richtext/text_format.png)
 </div>
 
 #### Markdown format
@@ -172,5 +172,5 @@ More shortcuts may be introduced in future updates.
 To get actual reference related to RichText keyboard shortcuts, press **Help** and select the **Keyboard shortcuts** option:
 
 <div className="img_border">
-![Keyboard shortcuts](/img/richtext/shortcut_reference.png)
+![DHTMLX RichText keyboard shortcuts reference window](/img/richtext/shortcut_reference.png)
 </div>

i18n/de/docusaurus-plugin-content-docs/current/guides/configuration.md

@@ -25,13 +25,13 @@ RichText unterstützt zwei Layout-Modi für den Bearbeitungsbereich:
 - `"classic"` — der Bearbeitungsbereich füllt die gesamte Seite aus
 
 <div className="img_border">
-![Klassischer Modus](/img/richtext/classic_mode.png)
+![DHTMLX RichText-Editor im klassischen Layout-Modus](/img/richtext/classic_mode.png)
 </div>
 
 - `"document"` — der Bearbeitungsbereich imitiert eine Dokumentseite
 
 <div className="img_border">
-![Dokumentmodus](/img/richtext/document_mode.png)
+![DHTMLX RichText-Editor im Dokumentmodus](/img/richtext/document_mode.png)
 </div>
 
 Legen Sie die Eigenschaft [`layoutMode`](api/config/layout-mode.md) bei der Initialisierung fest, um den Modus auszuwählen:

i18n/de/docusaurus-plugin-content-docs/current/guides/integration_with_angular.md

@@ -294,7 +294,7 @@ platformBrowserDynamic()
 Starten Sie die App, um zu sehen, wie RichText mit Daten auf der Seite gerendert wird.
 
 <div className="img_border">
-![RichText-Initialisierung](/img/trial_richtext.png)
+![In einer Angular-Anwendung gerendertes DHTMLX RichText mit Beispielinhalt](/img/trial_richtext.png)
 </div>
 
 Sie haben jetzt eine funktionierende RichText-Integration in Angular. Passen Sie den Code an Ihre Bedürfnisse an. Ein vollständiges Beispiel ist auf [GitHub](https://github.com/DHTMLX/angular-richtext-demo) verfügbar.

i18n/de/docusaurus-plugin-content-docs/current/guides/integration_with_react.md

@@ -247,7 +247,7 @@ useEffect(() => {
 Starten Sie die App, um zu sehen, wie RichText mit Daten auf der Seite gerendert wird.
 
 <div className="img_border">
-![RichText-Initialisierung](/img/trial_richtext.png)
+![In einer React-Anwendung gerendertes DHTMLX RichText mit Beispielinhalt](/img/trial_richtext.png)
 </div>
 
 Sie verfügen nun über eine funktionierende RichText-Integration in React. Passen Sie den Code an Ihre Anforderungen an. Ein vollständiges Beispiel ist auf [GitHub](https://github.com/DHTMLX/react-richtext-demo) verfügbar.