Unify secondary navigation items across themes, patterns, plugins

[jasmussen]

Across themes, patterns, plugin directories there are secondary navigation items we can improve the consistency of. Themes:

Plugins:

Patterns:

Using either title case or sentence case (with a small preference for leaning towards sentence case across) has been noted for some of the other directories. But at least it should be consistent. Across:

• Use "My favorites" or "My Favorites", not just "Favorites"
• Use the same case across.

[ryelle]

I think we've standardized on sentence case everywhere, so we should stick with "My favorites" — right @thetinyl?

[thetinyl]

@ryelle Confirming sentence case!

[ryelle]

Cool, then this can be closed for the theme directory, and individual issues should be opened in the Pattern directory and Plugins repos for updating those instances.