Accessibility: Administration: Underline links on Dashboard that are located within a line of text and thus need to be underlined:

* "change your theme completely"
* Active theme in the "At a Glance" box
* "View all drafts" in the Quick Draft box

Split "Manage widgets or menus" into separate items for consistency with other links.

For better accessibility, links that are a part of other text should be underlined and not rely on color alone to be distinguished.

Per accessibility coding standards:
> When links can be identified as such by the context, for example because they’re part of a menu, or a set of links clearly identified as user interface controls, they don’t necessarily need to be underlined. In all the other cases, especially for links surrounded by other text (in a line or block of text), links need to be always underlined.
https://make.wordpress.org/core/handbook/best-practices/coding-standards/accessibility-coding-standards/#links-underline-or-no-underline
https://make.wordpress.org/accessibility/handbook/design/use-of-color/#not-by-color-alone

Props afercia, audrasjb, karmatosed.
Fixes #48406.

git-svn-id: https://develop.svn.wordpress.org/trunk@46770 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/css/dashboard.css

@@ -130,7 +130,7 @@
 	color: #72777c;
 }
 
-.welcome-panel a {
+.welcome-panel li a {
 	text-decoration: none;
 }
 
@@ -260,6 +260,16 @@
 	top: -2px;
 }
 
+.welcome-panel .welcome-widgets:before {
+	content: "\f538";
+	top: -2px;
+}
+
+.welcome-panel .welcome-menus:before {
+	content: "\f163";
+	top: -2px;
+}
+
 .welcome-panel .welcome-comments:before {
 	content: "\f117";
 	top: -1px;
@@ -886,8 +896,9 @@ body #dashboard-widgets .postbox form .submit {
 	min-width: 0;
 }
 
-#dashboard-widgets a,
-#dashboard-widgets .button-link {
+#dashboard-widgets li a,
+#dashboard-widgets .button-link,
+.community-events-footer a {
 	text-decoration: none;
 }