Accessibility: Improve markup of Credits Screen

[mercime]

Our current screen has links that are adjacent to each other which point to the same reference and also has images with alt attributes that are the same as the adjacent texts in links. These make extra noise for screen reader users and also causes extra tabbing for those using their keyboards to navigate the screen.

The following images will be attached for reference:

• a screenshot of the before and after of screen reader outputs
• some animated gifs of keyboard navigation on BP/WP trunk, BPtrunk/WP 4.4.1, and BPtrunk/WP 3.9.

Upcoming patch will address these issues.

[mercime]

Before and after screen reader text

[mercime]

WP/BP trunk - keyboard navigation before patch

[mercime]

WP/BP trunk - keyboard navigation after patch

[mercime]

BPtrunk/WP 4.4.1 - keyboard navigation after patch

[mercime]

BPtrunk/WP 3.9 - keyboard navigation after patch

[mercime]

Refreshed patch

[mercime]

In 10534:

A11y: Simplify markup of the Credits panel to improve access to content.

Remove adjacent links and text to reduce noise for screen readers and
decrease tabbing for keyboard users while scanning the lists of
BuddyPress Project Leaders, Core Team, and Rockstars.

Fixes #6860.