Consider migrating the docs from Bootstrap to ReadTheDocs theme

[vitaut]

Advantages of the Bootstrap theme:

1. Mobile friendliness
2. Good default styles

Disadvantages of the Bootstrap theme:

1. Conflicts of CSS classes between Bootstrap and Docutils/Sphinx (Bootstrap classes prefix twbs/bootstrap#1287)
2. Primary use of navbar instead of sidebar navigation
3. Inherits all the Bootstrap issues (cluttered non-semantic markup, heavy etc).

Since the main reason for using the Bootstrap theme was mobile friendliness, it might be easier just to use a mobile-friendly Sphinx theme such as ReadTheDocs instead of addressing the issues with Bootstrap.

Advantages of the ReadTheDocs theme:

1. Mobile friendliness
2. Sidebar navigation works out of the box
3. Integration with ReadTheDocs
4. Large user base

Disadvantages of the ReadTheDocs theme:

1. Poor default styles, esp. for API
2. Doesn't look good on a tablet (at least in vertical mode) - the sidebar is too wide. The stock Sphinx theme is actually better.
3. Difficult to customize (issue 518)

[vitaut]

Possible alternative solutions to the class conflict:

1. Use custom HTML builder for Sphinx that adds prefixes to the conflicting class names.
2. Use semantic layout in Bootstrap. It is a good idea anyway, but does it solve the problem?

[vitaut]

Docutils bug #267 Name conflict for CSS class container

[vitaut]

Wrapping bootstrap.less in a namespace breaks many of its styles.

[vitaut]

Decided not to migrate to the ReadTheDocs theme because of the poor styles for API and because standard themes and the Bootstrap theme look better on tablets.