Update MR Approvals UI Text

Update this section of the UI to meet the Pajamas style guidelines: Settings > General > Merge Request Approvals.

(note: if you don't see "Merge Request Approvals" in your deployment, this requires an Ultimate (I think) license.)

Closes technical-writing#311 (closed)

Guidance

Remember: With UI text, less is more. If you need to go into detail, link to the docs.

Closes technical-writing#311 (closed)

Review grammar and style

At a minimum, address these issues:

• Present tense rather than future. https://design.gitlab.com/content/voice-tone#instructions
• Active voice. https://design.gitlab.com/content/voice-tone#active-voice
• No periods for settings or headings. https://design.gitlab.com/content/punctuation#periods
• Periods for all help text.
• No repetitive or unnecessary text. (Things like: This setting is... or "Use this setting to.")
• Oxford comma used correctly. (This, this, and this.)
• Language is parallel. (Review all the settings in the section to ensure they are similarly-worded.) https://design.gitlab.com/content/voice-tone#parallelism
• If a setting is optional, "optional" is in parentheses at the end of the setting name. https://design.gitlab.com/components/form/#required-information
• Latinisms (i.e., e.g.) removed. https://design.gitlab.com/content/voice-tone#avoid-latin-abbreviations
• Don't use "allow" unless you're specifically talking about security. For example, "Allows users to fork the repo" should be "Users can fork the repo."
• Do a final review of everything you've updated and consider whether it affects the docs. If it does, open a follow-up issue or an MR to update the docs.

Do not change the text for settings themselves. If you do feel strongly that a setting name should be changed, open a follow-up issue and work with a PM to change it. When you change a setting, the related docs also need to change. These changes are outside the scope of this issue.

Screenshots (strongly suggested)

• Before and after

Before	After

Note: The "Require approval from CODEOWNERS" setting was moved to [Protected Branches] line is outside the scope of the target modal, and is not covered in this MR.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team