Moves the install related sections of the FAQ to the install docs because I think that would make them more discoverable and ended up editing/consolidating some of the install docs to make these changes smoother.

summary of changes:

• move environment variables to install because it's install and environment config related

• moved git related troubleshooting to devel docs

  • also added in DLL troubleshooting per [gitter convo](https://matrix.to/#/!BXmyZMTnRjWJldDRLV:gitter.im/$4A08jkGMiIEgV3MaUFYoJ2vCVoBMir5JMovSKCfmsGA?via=gitter.im&via=matrix.org&via=aria-net.org

• moved install related troubleshooting to a file in install

  • included this file in install docs
  • linked out to this file from the development troubleshooting guide

• added env variables and troubleshooting to the install and workflow listings on the devel index

• movedget in touch to main faq doc - I don't think we need this given we have this section in our contributor guide but also trying to scope current changes mostly to install 🤷‍♀️

• moved main faq doc up to users and removed faq folder because it's now 1 document

• consolidated install docs:

  • removed the install from github instructions from "install from source" and replaced with giant note to see install for development
  • moved windows visual studio instructions to dependencies
  • add first step dependencies to develop install docs