Remove logstash from downloads page and fix blog

[derek-ho]

Description

Removes logstash from downloads page and adds more info for blog on connecting your own self managed OSD.

Issues Resolved

Fix: #3427
Fix: #3426

Check List

• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the BSD-3-Clause License.

[derek-ho]

@cwperks can you help take a look for technical accuracy? Also @pajuric I am not too familiar with the downloads page. Will removing this file remove the entry from the page?

[nateynateynate]

Hey @derek-ho - _include/downloads/logstash-oss-with-opensearch-output-plugin.markdown is referenced in many other locations. I don't think we can safely delete it unless we find the references to it.

I forget where the logic is that constructs the view of the download page, but give me a bit and I'll drop some hints in here.

[nateynateynate]

It's always a good idea to try to build the site locally so we can see what build errors are going to pop up. The output of that will lead us to what's going wrong.

[nateynateynate]

This file cannot be safely deleted unless we find all the places its being used. Try running bundle exec jekyll serve from the root of the repo and going through the list of errors. It should give us some hints.

[nateynateynate]

This might help:

It looks like a lot of the files in _versions reference that file as the explanation metadata. I'd start there.

[derek-ho]

@cwperks @dblock I am working on this PR but a little confused on how to proceed here. Should we remove the logstash in general, or only going forward?