Only re-render markdown in getting-started steps if it contains code …

…blocks (microsoft#170135)

Only re-render markdown in gs step if it contains code blocks

src/vs/workbench/contrib/welcomeGettingStarted/browser/gettingStarted.ts

@@ -609,14 +609,16 @@ export class GettingStartedPage extends EditorPane {
 				}
 			}));
 
-			this.stepDisposables.add(this.themeService.onDidColorThemeChange(async () => {
-				// Render again since syntax highlighting of code blocks may have changed
-				const body = await this.detailsRenderer.renderMarkdown(media.path, media.base);
-				if (!isDisposed) { // Make sure we weren't disposed of in the meantime
-					webview.html = body;
-					postTrueKeysMessage();
-				}
-			}));
+			if (rawHTML.indexOf('<code>') >= 0) {
+				// Render again when Theme changes since syntax highlighting of code blocks may have changed
+				this.stepDisposables.add(this.themeService.onDidColorThemeChange(async () => {
+					const body = await this.detailsRenderer.renderMarkdown(media.path, media.base);
+					if (!isDisposed) { // Make sure we weren't disposed of in the meantime
+						webview.html = body;
+						postTrueKeysMessage();
+					}
+				}));
+			}
 
 			const layoutDelayer = new Delayer(50);