doc (BUILDING.md): add Fedora install guide, and build from source without running guide

[Owen-sz]

This is useful for people who do not want to run the program right away, and for packaging.

[twvd]

Thank you! Are you packaging Snow for Fedora? If so, do you mind installing the binary named as 'snowemu'? This is what other distros have also been doing. If you have any suggestions on how to properly document this, please let me know.

[Owen-sz]

Thank you! Are you packaging Snow for Fedora? If so, do you mind installing the binary named as 'snowemu'? This is what other distros have also been doing. If you have any suggestions on how to properly document this, please let me know.

I packaged it for Terra, a third party Fedora repo.
Here's the PR for that - terrapkg/packages#8562
Actually just got merged before your comment, I will patch the binary name right now.

I've seen many other projects have a Packaging.md, but we may just want to add onto another file since it would (probably) be pretty short. I can look to see what file that can fit best onto and PR that in the coming days.

Also, in my Terra PR I added a metainfo.xml and .desktop file, and was thinking of just PRing those here as well. Is that something you'd be interested in?

[twvd]

Definitely, it might be good to standardize those.

Note there's also a package for Nix: https://github.com/NixOS/nixpkgs/blob/nixos-25.11/pkgs/by-name/sn/snowemu/package.nix
and OpenSUSE (website is down for me right now..).

I will also add a table on the website at some point with a list of distro packages.

[Owen-sz]

Sounds good! I will get these in order after the holidays and make a couple PRs