Fix issue #116591 (#116885)

* Fix Extension README not correctly displaying HTML

* Supports common html attributes

* Remove extra attributes
Co-authored-by: NAnton Volokha <antonvolokha@gmail.com>

src/vs/workbench/contrib/extensions/browser/extensionEditor.ts

@@ -69,6 +69,17 @@ import { insane } from 'vs/base/common/insane/insane';
 
 function removeEmbeddedSVGs(documentContent: string): string {
 	return insane(documentContent, {
+		allowedTags: [
+			'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'h7', 'h8', 'br', 'b', 'i', 'strong', 'em', 'a', 'pre', 'code', 'img', 'tt',
+			'div', 'ins', 'del', 'sup', 'sub', 'p', 'ol', 'ul', 'table', 'thead', 'tbody', 'tfoot', 'blockquote', 'dl', 'dt',
+			'dd', 'kbd', 'q', 'samp', 'var', 'hr', 'ruby', 'rt', 'rp', 'li', 'tr', 'td', 'th', 's', 'strike', 'summary', 'details',
+			'caption', 'figure', 'figcaption', 'abbr', 'bdo', 'cite', 'dfn', 'mark', 'small', 'span', 'time', 'wbr'
+		],
+		allowedAttributes: {
+			'*': [
+				'align',
+			]
+		},
 		filter(token: { tag: string, attrs: { readonly [key: string]: string } }): boolean {
 			return token.tag !== 'svg';
 		}