Fix documentation build warnings

[brianhelba]

Fixes as many Sphinx warnings as possible.

• Sphinx build log from a recent latest build.
• Sphinx build log from this PR.

Checklist

• PR only contains one change (considered splitting up PR)
• unit-test added
• documentation updated
• CHANGELOG.md updated (only for user relevant changes)
• author name in AUTHORS
• tests/app/idp updated to demonstrate new features
• tests/app/rp updated to demonstrate new features

[brianhelba]

Sphinx complains:

WARNING: duplicate object description of oauth2_provider.views.mixins, other instance in views/details, use :no-index: for one of them

This is already fully documented here:

django-oauth-toolkit/docs/views/details.rst

Lines 18 to 19 in dbedfaa

	.. automodule:: oauth2_provider.views.mixins
	:members:

Since the other reference has more context and the mixins are indeed more internal than user-facing, keep only those docs.

[brianhelba]

Sphinx complains:

Skip system checks.' as "sh" resulted in an error at token: "'". Retrying in relaxed mode.

console makes more sense: https://pygments.org/docs/lexers/#pygments.lexers.shell.BashSessionLexer

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[brianhelba]

Other parts of this file use a syntax like :rfc:`2.2`, which is parsed by

django-oauth-toolkit/docs/rfc.py

Line 11 in dbedfaa

def rfclink(name, rawtext, text, lineno, inliner, options={}, content=[]):

No such support actually exists for a :openid:`2` syntax.

However, it's apparent that this is the intended external link.

[brianhelba]

@dopry Please take a look.