Split up infrastructure page

I'm looking at our [infrastructure](https://conda-forge.org/docs/maintainer/infrastructure/) page, and it's pretty long and unwieldy.

I think it should be split up, possibly into several different pages. At the very least, I'd like to split it into stuff that's recipe-relevant (compilers, sysroot, CDTs), and stuff that regular maintainers need much less often (website, metadata, CI setup, etc.).

Other possible things that might deserve their own pages:
* bot commands
* staged-recipes
* "special package handling" (i.e. repodata patches, admin requests, feedstock-outputs)
* everything regro-related

Thoughts @conda-forge/core?

CC @zklaus for recent efforts on these pages.