Fix font-weight (fixes #19172)

src/vs/workbench/parts/welcome/page/electron-browser/welcomePage.css

@@ -199,6 +199,7 @@
 }
 
 .monaco-workbench > .part.editor > .content .welcomePage .commands li button h3 {
+	font-weight: normal;
 	font-size: 1em;
 	margin: 0;
 	margin-bottom: .25em;

src/vs/workbench/parts/welcome/walkThrough/electron-browser/walkThroughPart.css

@@ -35,7 +35,9 @@
 	border-bottom: 2px solid;
 }
 
-.monaco-workbench > .part.editor > .content .walkThroughContent h1, h2, h3 {
+.monaco-workbench > .part.editor > .content .walkThroughContent h1,
+.monaco-workbench > .part.editor > .content .walkThroughContent h2,
+.monaco-workbench > .part.editor > .content .walkThroughContent h3 {
 	font-weight: lighter;
 	margin-top: 20px;
 	margin-bottom: 10px;