[Evergreen-documentation] Server build docs issue

[Blake Graham-Henderson]

All,

On today's call, we figured out that the docs haven't been generating 
since November 17th. There are node error reports on the server's hard 
drive indicating that it's been running out of memory. Looking deeper, 
that was the day that we added rel_3_12 branch to the list of branches 
we're asking it to generate. That was apparently one too many, and it 
has exceeded the 2GB memory limit that Node.js imposes itself. I've 
edited the generation script to allow for 4GB memory instead, and it 
finished! So, the website now has all of the latest stuff.

A secondary issue: the non-main branches were not getting the latest 
documentation.

This was due to a flaw in the documentation script. It wasn't running 
through all of the branches and pulling the latest git changes. I've 
introduced a chunk of code in that bash script that does that now.

Any system admins that need to know more: when a new branch is 
introduced, we're going to need to reference it in the build script 
~antora/run_docs

...
for branch in "rel_3_12" "rel_3_11"  "rel_3_10" "rel_3_9" "rel_3_8" 
"rel_3_7" "rel_3_6" "main";
...

-- 
-Blake-
Conducting Magic
Will consume any data format
MOBIUS