[MRG] updating content from zexuan's user test

[choldgraf]

• Add / update documentation

This PR:

• updates several sections, clarifies points, adds some new content, and rearranges the index page so that it is broken down by topic instead of one flat "howto" list.
• Removes the tutorials section for now (with the idea that we may add it back later when there is more content to fill in that section).
• Adds a CSS rule so the title fits
• Updates some REFs that were broken
• Splits up the docs requirements files into two files so that we can get the docs tests to pass

[betatim]

Oathenticator -> Oauthenticator

[choldgraf]

Just rebased so the integration tests should pass and there aren't any more conflicts. Also fixed @betatim 's typo spot.

[choldgraf]

Also split up the docs requirements files into two files so that we can get the docs tests to pass

[yuvipanda]

@choldgraf tyvm for the patch! I've made two changs: rename 'envt' to 'env', and remove the FAQ section. I don't think the sudo -E explanation belongs in FAQ, but I can't figure out a nice place to put it. So instead i'm just going to remove requiring sudo -E for most things in a different PR. Hope that's ok!

[yuvipanda]

#135 removes -E from all tljh-config commands. I'll think about how to remove it from conda and pip commands.

[yuvipanda]

@choldgraf just a quick note - I see you had added 'sudo -E' for apt, mkdir etc too in this PR. Those are not necessary. The only commands -E is needed for is tljh-config, the pip and conda we install into the user environments. I've fixed these up as part of #135

[choldgraf]

Cool! No worries. I was putting sudo - E in front of everything just for consistency. It seemed confusing to tell people to only use it sometimes and not other times. If it's used rarely enough, I don't think it's a big dealt tho