Add in all wiki articles from now defunct atom

[confused-Techie]

In this PR I've added all the old Atom wikis.

I had originally moved this into our old documentation under a special wiki only section, but since we've remapped the entire website, I took this chance to instead group things in a more logical way.

Adding the autocomplete-plus data into infrastructure since anyone wanting to write a package for autocomplete+ would likely to expect to find the information there, alongside other documentation about integrating with core features.

Since other wiki articles like ide-java and atom-languageclient detailed information more about maintaining a package, I added those to the maintaining-pulsar section.

Lastly, the github package wiki doesn't do any of those things, but I do find it a cool nugget of history about the project, so also added it to maintaining-pulsar.

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When I originally checked every single package repo (when I originally had forked all of them to Pulsar) these were the ones I identified as having a wiki, so this PR should constitute every single wiki, and entry that exists in the Atom organization. Since I would very much like to make sure we archive this data, it seems rather reasonable to add it here, more-so in the case of helpful documentation like for autocomplete+