Update semgrep to run for javascript

What does this MR do?

• Update docs to say that the semgrep analyzer can analyze JavaScript, TypeScript, and React files.
• Update the SAST CI Template run the semgrep analyzer for JavaScript, TypeScript, and React files.

Related Issue

#322196 (closed)

Manual QA

https://gitlab.com/gitlab-org/security-products/tests/python-pip-flask/-/pipelines/264469968 shows that the change in gitlab-org/security-products/tests/python-pip-flask!4 (diffs) to use this branches version of the SAST.gitlab-ci.yml file was successful and didn't break.

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