Add whole codebase semantic indexing setting

[AlexandraKemperMS]

Added options for enabling whole codebase semantic indexing and detailed descriptions of their effects on system resources.

[prmerger-automator]

@AlexandraKemperMS : 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 7950ecd:

✅ Validation status: passed

File	Status	Preview URL	Details
docs/ide/configure-languages-c-cpp-intellisense.md	✅Succeeded

For more details, please refer to the build report.

[v-regandowner]

Hi @AlexandraKemperMS - This pull request was opened in the public repo. PMs should work in the private repo, per the Microsoft Docs contributor guide. We can keep this PR open for review and merge, but would you make future content updates in the private repo? Thank you!

@GitHubber17

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

[AlexandraKemperMS]

@v-regandowner thanks for letting me know, let's actually close this and do the review in the private repo

[ghogen]

@TylerMSFT
This is a submission on one of the articles that Beth-Anne Harvey created recently on C++ settings. Can you review the proposed changes?

[learn-build-service-prod]

Learn Build status updates of commit 2e702de:

✅ Validation status: passed

File	Status	Preview URL	Details
docs/ide/configure-languages-c-cpp-intellisense.md	✅Succeeded

For more details, please refer to the build report.