Add CustomGPT post and remove fellows/interns listings

[cloudcannon]

Publishing Kristi's blog post about making custom GPTs for professors, also removing the intern/fellowship postings on the jobs page.

[rebeccacremona]

Hmmmmmm. It is difficult for me to tell exactly what happened here... It looks like there was some excitement in git, that did not go well.

For instance, I'm not sure what occurred that resulted in this commit that says @clare-stanton updated three files via Cloudcannon (edaad97), and the changes include applying the updates Eric made in this PR e7f0046.

Similarly, looks like maybe there are vestiges of an attempt to add the AALL blog post via Cloudcannon (3f5f633), though that post was in fact added via a PR from a feature branch to develop (#700).

I'm going to do some surgery to get this branch into a clean state.

If I am reading this correctly, the only intended changes are a) add the new blog post, and b) remove the category "research" from those two job listings, so that the files remain in the repository, but the listings don't appear on the Jobs page.

@kmukk Should the new blog post be backdated to February 15, 2025?

[clare-stanton]

@rebeccacremona Oh gosh... thanks for the untangling. You are correct, the purpose of this PR is to add the Custom GPT blog post (which is intentionally backdated) and remove the fellows and interns listing from the live site without deleting the files.

[rebeccacremona]

I noticed that the strategy of just removing the category, so as to hang onto the job listings without displaying them, broke the logic for page spacing.

instead of

So, instead, I switched them to published=false, and tweaked the spacing logic.