Add More Options to Configure Italicization

[agrzeslak]

Before this commit, it was possible to enable italicization of strings and comments. This seems fairly arbitrary as users (myself included) may want to choose settings other than these. For instance, some other themes use italicization to separate keywords, or other language-specific patterns. While this may not be of interest to everyone, it seems reasonable to allow it to be configurable.

This patch therefore introduces the following configuration options:

• g:gruvbox_italicize_statements
• g:gruvbox_italicize_conditionals
• g:gruvbox_italicize_repeats
• g:gruvbox_italicize_label
• g:gruvbox_italicize_exceptions
• g:gruvbox_italicize_keywords

If this is an acceptable change, I'm happy to also update the wiki documentation to match.

[rbong]

It seems not obvious to me if these should be options or not.

It may be better to focus on a couple recommended highlight groups to enable italics for and leave the rest to :hi if you want more customization.

I will leave this open to more feedback - I don't use italics. Just wanted to share that it's not obvious to me if we should merge.

[agrzeslak]

@rbong completely fair and understandable, especially to avoid ongoing creep in the amount of options. If there's interest in adding some more customisation, but in a more palatable form, then I'd be more than happy to change the mechanism through which this happens. I'll go back and see if I can think of something different that may work better. Thanks for the feedback!