Adjust heading structure for pages using wp-admin/css/install.css

The readme, installation, upgrade, and repair pages use a common css file. The heading structure for these pages was inconstant with h2s where there should be h1s, h1s where there is no relevant info and sometimes, no h1s at all.

Fixes #34519
Props rianrietveld



git-svn-id: https://develop.svn.wordpress.org/trunk@35508 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/css/install.css

@@ -38,7 +38,7 @@ a:focus {
 	outline: #5b9dd9 solid 1px;
 }
 
-h1 {
+h1, h2 {
 	border-bottom: 1px solid #dedede;
 	clear: both;
 	color: #666;
@@ -49,7 +49,7 @@ h1 {
 	font-weight: normal;
 }
 
-h2 {
+h3 {
 	font-size: 16px;
 }
 
@@ -87,6 +87,7 @@ label {
 
 #logo {
 	margin: 6px 0 14px 0;
+	padding: 0 0 7px 0;
 	border-bottom: none;
 	text-align:center
 }