Use Title Case consistently in card titles, to match Calypso

[MichaelArestad]

Changes proposed in this Pull Request:

• removes title case in settings headings

Testing instructions:

• Go to Settings and check all the headings to make sure they are not using Title Case

@zinigor @eliorivero or @georgestephanis I couldn't figure out how to change it for all of them. Can one of you fix these:

• Custom Content Types > Custom content types
• Related Posts > Related posts
• Site Verification > Site verification

[eliorivero]

Those are using the module name as is defined in the module file header. Would you prefer to update the module file or add a custom, no capitalized, string in JS?

Note that if the module file header, for example, modules/related-posts.php is updated, the changes are not instantaneous because it's read from modules/module-headings.php which is updated after a yarn build (but can be also manually updated for testing purposes).

[beaulebens]

From what I can tell, every heading in Calypso uses title case, while every option/label uses sentence case. I think we should be matching that, which means we should be ensuring that headings are title case in Jetpack.

[beaulebens]

The places that I found which do not already have Title Case (e.g. which would need to be updated) are;

• Security > Backups and security scanning
• Security > Brute force protection
• Security > WordPress.com log in
• Traffic > Site stats
• Writing > Theme enhancements

[eliorivero]

@beaulebens this change was causing a major JS error on Writing tab. I've reverted it to the way I wrote it, without the curly braces since the imported component is the default exported.

[beaulebens]

Ah cool. I made that change when resolving a conflict, just to match the others. 👍

[MichaelArestad]

It looks like after a discussion in Slack, we should be using sentence case for all of these headings as per our branding guidelines: https://dotcombrand.wordpress.com/brand-voice/#style

Calypso will need to be updated eventually to match.

[eliorivero]

Closing this in favor of #6394 since this one was doing title case and we'll be doing sentence case plus it has a bunch of conflicts.