Broken Telecomunications Act links

[dafydd61]

My first attempt to contribute, so I apologize in advance if I waste your time...

Several links pertaining to the Telecommunications Act (US) are resulting in 404s on the Access Board site:

wai-policies-prototype/_policies/united-states.md

Line 110 in 87d7172

en: https://www.access-board.gov/the-board/laws/telecommunications-act

It looks to me like this may be corrected using https://www.access-board.gov/law/ta.html

I can't find appropriate candidates for the following links::

wai-policies-prototype/_policies/united-states.md

Line 131 in 87d7172

en: http://www.access-board.gov/guidelines-and-standards/communications-and-it/about-the-telecommunications-act-guidelines/section-255-guidelines

wai-policies-prototype/_policies/united-states.md

Line 140 in 87d7172

en: https://www.access-board.gov/guidelines-and-standards/communications-and-it/about-the-telecommunications-act-guidelines/guidance-on-the-telecommunications-act-%C2%A7255-guidelines