Resolve wrong stl::less and clean up "Collections (C++/CX)"

[Rageking8]

• Resolve typo of std::less as stl::less
• Bunch of cleanups

I recommend reviewing the changes one commit at a time or else the diff might get unwieldy.

[prmerger-automator]

@Rageking8 : Thanks for your contribution! The author(s) and reviewer(s) have been notified to review your proposed change.

[learn-build-service-prod]

Learn Build status updates of commit 8965e98:

✅ Validation status: passed

File	Status	Preview URL	Details
docs/cppcx/collections-c-cx.md	✅Succeeded

For more details, please refer to the build report.

[prmerger-automator]

PRMerger Results

Issue	Description
File Change Percent	This PR contains file(s) with more than 30% file change.

[learn-build-service-prod]

Learn Build status updates of commit 3572cc9:

✅ Validation status: passed

File	Status	Preview URL	Details
docs/cppcx/collections-c-cx.md	✅Succeeded

For more details, please refer to the build report.

[prmerger-automator]

PRMerger Results

Issue	Description
File Change Percent	This PR contains file(s) with more than 30% file change.

[v-regandowner]

@TylerMSFT - Can you review the proposed changes?

IMPORTANT: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged"
@MicrosoftDocs/public-repo-pr-review-team