Adding Accessibility Page

[metageeky]

Adds the accessibility page (complete with navigation) to website

[phette23]

Couple HTML typos in /accessibility/index.html:

• in the href for Aaron Collier's email on line 66 which breaks the mailto
• mismatched open/close <li>s, floating letter "o" on lines 90-91

Push a fix for that & then it's good to go! 👍

[phette23]

Merging but will push a fix right after.