Code QL pre-migration tasks: update articles relating to CodeQL for JavaScript

[mchammer01]

See https://github.com/github/product-documentation/issues/2165 for details.
The first commit changes titles.

[mchammer01]

2nd commit adds some intros but I'm afraid I won't get much further before we have to leave for the mini-summit.

[mchammer01]

Please note that I haven't made any changes to do with content models and localization checklists.

[mchammer01]

Thanks for the valuable review @intrigus-lgtm 👍
This PR has been raised as a draft so I wasn't expecting reviews just yet 😉
It's just a starting point and I have a lot more work to do but I'll ensure I'll take your comments (especially the ones about the typos 😱 ) into consideration.
Our documentation is written in American English but I know that we need to rationalize spellings and check that this is true throughout the whole set of articles. This work is part of the migration of the CodeQL documentation and has just started so please bear with us while we improve things.
Thanks again for your help!

[mchammer01]

This PR is now ready for review.
The work in this PR contains pre-migration tasks for the CodeQL documentation. This includes:

• updating article titles
• adding intros to each article
• updating links as per the new article title
• change the What next section title to Further reading

[mchammer01]

Apologies for the automatic review request @jf205 and @shati-patel but I can't seem to be able to remove that (no cog icon for me to the right of the Reviewers section on the right hand-side). Is this due to a permissions thing on this repo?

[felicitymay]

Since this is small text changes, I'm removing @jf205 ad @shati-patel as reviewers. Anyone in the docs team can review this PR.

[felicitymay]

Thanks for the update. The new titles and associated changes to links look good.

Could you review the introductions? I'm not sure all articles have one (probably because you were interrupted in the middle of this work).

[mchammer01]

@felicitymay - thanks for your review. I believe I have addressed your comments.
I am keen to get this merged today, as discussed in our team meeting.
We can still iterate if there are further things to tweak or rationalize between languages.

[felicitymay]

Thanks for the additional introductions. A couple of very minor suggestions. Ready to merge once you've accepted/rejected those suggestions.

[mchammer01]

@felicitymay - I have accepted your suggestions. Can you double-check you are ok with things now? Thanks.

[felicitymay]

All LGTM 💚