Add documentation for the Tailscale service #458

[FroggyFlox]

Fixes #458 @phillxnet, @Hooverdan96: ready for review.

This pull request's proposal

This pull-request adds a basic documentation on the Tailscale service:

• configuration options
• important requirements
• how to login/authenticate

• what to expect on the created networks

  This commit also includes a fix for Sphinx's basic css theme that was not properly loaded as we expect. This corrects all images that weren't actually aligned even though they were defined to be.

Finally, the entire services.rst was reformatted (including minor typo corrections) in an effort to follow semantic linefeeds.

Checklist

• [x] With the proposed changes no Sphinx errors or warnings are generated.
• [x] I have added my name to the AUTHORS file, if required (descending alphabetical order).

[phillxnet]

@FroggyFlox Curiously the linkcheck here (run within buildbot) passed without issue.

Link check complete; look for any errors in the above output  or in _build/linkcheck/output.txt.
program finished with exit code 0

So it looks like a timeout on this url:

(interface/overview: line  197) broken    https://www.minecraft.net/en-us/ - HTTPSConnectionPool(host='www.minecraft.net', port=443): Read timed out. (read timeout=20)

[phillxnet]

PR product PRODUCTION published.