a11y imporvements to wiki/history.html

[symbolist]

https://edx-wiki.atlassian.net/browse/LMS-1309

1. When a revision diff details are toggled on the focus is moved to the diff details div. Previously bootstrap collapse() was being used which changed the url anchor before displaying the corresponding details div causing screen readers to start reading from the start.
2. Added scope attribute to th elements to associate header information with the cells. See http://www.w3.org/TR/html4/struct/tables.html#h-11.4.1 for details.

[symbolist]

Annotate table cells.

[caesar2164]

Follows W3 table a11y syntax so, this lgtm...

[symbolist]

@caesar2164 here is one for you too.. and @adampalay another one for you. :)

[caesar2164]

probably want to remove your dev console statement?

[symbolist]

Will do when I rebase.

[caesar2164]

Hi @symbolist this PR looks like a very good start. Before I ok it to merge, I'd like to see feedback from someone that better understands the JSON accordion loading (@adampalay ?) just to make sure that works as expected, but accessibility wise this seems to make a lot of sense...

[sarina]

@symbolist just a note - please put the JIRA ticket ID in your commit message going forward (ie

commit message

LMS-xxxx

This helps us compile our release notes.

[symbolist]

Removed console.log() call, rebased, added ticket ID to commit message and tested on IE10+Jaws and ChromeVox.

[adampalay]

👍

[caesar2164]

LGTM 👍