[build] Fix vulnerability in showdown

... by replacing it with markdown-it and adding sanitization

```
npm audit report

showdown  *
Severity: moderate
Showdown vulnerable to Regular Expression Denial of Service (ReDoS) in link/anchor parsing - GHSA-rmmh-p597-ppvv
No fix available
node_modules/showdown
```

Fixes: https://github.com/redhat-developer/vscode-openshift-tools/security/dependabot/156

Signed-off-by: Victor Rubezhny <vrubezhny@redhat.com>

Author: vrubezhny

package-lock.json

@@ -150,6 +150,7 @@
 		"json-to-ast": "^2.1.0",
 		"leasot": "^14.4.0",
 		"lodash": "^4.18.1",
+		"markdown-it": "^14.1.1",
 		"mkdirp": "^3.0.1",
 		"mocha": "^11.7.5",
 		"module-alias": "^2.3.4",
@@ -168,7 +169,6 @@
 		"remap-istanbul": "^0.13.0",
 		"rxjs": "^7.8.2",
 		"semver": "^7.7.4",
-		"showdown": "^2.1.0",
 		"shx": "^0.4.0",
 		"sinon": "^21.1.2",
 		"sinon-chai": "^4.0.1",

package.json

@@ -36,9 +36,10 @@ import type {
 } from '@rjsf/utils';
 import { getTemplate, getUiOptions } from '@rjsf/utils';
 import validator from '@rjsf/validator-ajv8';
+import DOMPurify from 'dompurify';
+import MarkdownIt from 'markdown-it';
 import * as React from 'react';
 import 'react-dom';
-import { Converter } from 'showdown';
 import type { CustomResourceDefinitionStub } from '../../common/createServiceTypes';
 import { ErrorPage } from '../../common/errorPage';
 import { LoadScreen } from '../../common/loading';
@@ -197,10 +198,19 @@ function SelectService(props: {
 }) {
     const [isServiceKindTouched, setServiceKindTouched] = React.useState(false);
 
-    const converter = React.useMemo(() => {
-        return new Converter();
+    const md = React.useMemo(() => {
+        return new MarkdownIt({
+            html: false,
+            linkify: true,
+            typographer: true,
+        });
     }, []);
 
+    const safeConvertToHtml = (textToConvert) => {
+        const rawHtml = md.render(textToConvert);
+        return DOMPurify.sanitize(rawHtml);
+    };
+
     const [isDocumentationExpanded, setDocumentationExpanded] = React.useState(true);
 
     return (
@@ -275,7 +285,7 @@ function SelectService(props: {
                                 <Box margin={1}>
                                     <div
                                         dangerouslySetInnerHTML={{
-                                            __html: converter.makeHtml(
+                                            __html: safeConvertToHtml(
                                                 props.selectedServiceKind.csvDescription,
                                             ),
                                         }}