policy/documentation: consider updates to inclusion guidelines

[jlovejoy]

as per discussion on #1992 - it's probably a good time to have a look at how the inclusion guidelines are working and how we might clarify them.

For example, we added a couple points in the process https://github.com/spdx/license-list-XML/blob/main/DOCS/request-new-license.md
see 1 in the request part about non-FOSS license for a personal project and review section regarding licenses that have met the criteria for Debian or Fedora - probably should be in inclusion guidelines

also consider changing order of priority of factors

[jlovejoy]

also see @richardfontana feedback on use of "free" here as explained in #1979 whenever we do any kind of update.