Merge pull request #47 from DHTMLX/next

[remove] outdated v2.1 references from docs

Author: mafanya23

docs/deprecated_doc.md

@@ -6,10 +6,6 @@ description: You can study developer and user guides in the documentation of the
 
 # Guides
 
-:::info
-This documentation is dedicated to the renewed DHTMLX Spreadsheet of version **3.0 and upper**. To get information about the previous version **2.1**, [follow the related documentation](https://docs.dhtmlx.com/spreadsheet__index.html).
-:::
-
 DHTMLX Spreadsheet provides a range of great features to build a perfect application that include: support for import/export of data in different formats, handy work with content and style of data, adaptable structure of a spreadsheet, readonly mode, wide possibilities for look and feel customization, integration with famous frameworks, etc.
 
 ## Developer guides

docs/guides.md

@@ -6,8 +6,6 @@ description: You can learn how to start with the DHTMLX JavaScript Spreadsheet l
 
 # How to start
 
-{{note This documentation is dedicated to the renewed DHTMLX Spreadsheet of version 3.0. To get information about the previous version 2.1, [follow the related documentation](https://docs.dhtmlx.com/spreadsheet__index.html).}}
-
 This clear and comprehensive tutorial will guide your through the steps you need to complete in order to get a full-functional DHTMLX Spreadsheet on a page. The component will be especially effective for managing large amounts of data when you need to save the results of calculations and reproduce them.
 
 ![Spreadsheet init](assets/how_to_start.png)

docs/how_to_start.md

@@ -202,9 +202,11 @@ const locale = {
 
 ## 2.1 -> 3.0
 
-This list of changes will help you to migrate from the [previous version 2.1](https://docs.dhtmlx.com/spreadsheet__index.html) where DHTMLX Spreadsheet was PHP-based to the totally renewed version 3.0 in which the component is totally built on JavaScript. Check the list below to explore all the changes.
+This list of changes will help you to migrate from the previous version 2.1 where DHTMLX Spreadsheet was PHP-based to the totally renewed version 3.0 in which the component is totally built on JavaScript. Check the list below to explore all the changes.
 
-{{note The [API of version 2.1](https://docs.dhtmlx.com/spreadsheet__reference.html) is still available, but it is incompatible with the [API of version 3.0](api/api_overview.md).}}
+:::info
+The **API of version 2.1** is still available, but it is incompatible with the [**API starting from version 3.0**](api/api_overview.md). If you require the documentation for version 2.1, please [contact us](https://dhtmlx.com/docs/contact.shtml), and we will send it to you.
+:::
 
 ### Changed API
 

docs/migration.md

@@ -746,7 +746,7 @@ Released on October 25, 2018
 
 In comparison to the previous PHP-based version, DHTMLX Spreadsheet of version 3.0 is a completely client-side JavaScript component.
 
-Check the [Migration](migration.md) article to get information about the usage of new API. If you feel like keep using the previous version for a while, [the documentation for DHTMLX Spreadsheet v2.1](https://docs.dhtmlx.com/spreadsheet__index.html) is still available.
+Check the [Migration](migration.md#21---30) article to get information about the usage of new API.
 
 ### New functionality
 

docs/whats_new.md

@@ -23,8 +23,7 @@ module.exports = {
             },
             items: [
                 "whats_new",
-                "migration",
-                "deprecated_doc"
+                "migration"
             ]
         },
         {