Update themes-settings.html and strings.js

[Denisov21]

Fix #8712 (part 1 of 2)

[redmunds]

@Denisov21 Please put all of you files in a single pull request. I tried explain this in the Code Review section in this article, but maybe I wasn't clear enough. In you particular case, do this:

1. After submitting your first pull request (this one), look at the top where it says: "Denisov21 wants to merge 2 commits into adobe:master from Denisov21:patch-12 "
2. Go to your github fork of brackets page: github.com/Denisov21/brackets
3. Click on the Branches Tab
4. Click on the link to branch patch-12
5. All changes from there will be to this same pull request.

[redmunds]

@Denisov21 FYI, I updated the NLS README file with this section: Updating Existing Branch and Pull Request to make this more clear. Let me know if you have any suggestions for improvements.

[peterflynn]

Yep. We can't merge this without the changes in #8716 being part of the same merge. There's no reason for this to be split into 2 PRs (or even 2 separate commits, really).

[Denisov21]

@redmunds Sorry for the inconvenience, it was my first PR with two different files. Your explanation is very good!
@redmunds @peterflynn Changes made -- ready for another review

[MiguelCastillo]

Strings.THEME_SETTINGS does not match what you have defined in strings.js.

[Denisov21]

@MiguelCastillo Changes made -- ready for another review!

[MiguelCastillo]

This one looks good to be merged.

[ingorichter]

Thanks @Denisov21!