Added documentation for Steam Deck installation

[ProtocolNebula]

I've added the commands necessary to install in steam deck, the first time I did it took me like an hour or two due a lot of errors, so will be great to have the docs accessible for all users.

[0xDEADCADE]

It should be noted that the Steam Deck resets its rootfs on update, and sometimes reboot after a crash due to integrity checks.

While these instructions will install yay, it is not permanent, and steamos-readonly disable would need to be used after every reboot when a package needs to be installed or updated. A decent chunk of files from packages in base-devel and other packages (specifically header files) are missing from SteamOS by default, so many AUR packages will fail to build without manually reinstalling repository dependencies. SteamOS is also not rolling release, and is behind Arch Linux repositories, making the yay-bin package potentially incompatible due to library updates. Maybe include warnings for these SteamOS specific quirks?

It is also possible to install ArchLinux in something similar to distrobox, which doesn't have the SteamOS specific downsides, and can use the generic Arch Linux install instructions.

[ProtocolNebula]

I have Steam Deck for just 2 weeks and I had no problem yet related to the dependencies removal or required to execute steamos-readonly disable.

For sure, there are some packages that have troubles, but I'm not linux pro to solve that. I'm struggling to change the installation folder for pacman (and yay) and is giving some headaches related to the paths/system integration.

[Jguer]

I do not own a steam deck so I can't be sure if the instructions are correct, but I appreciate adding these in.

I think adding the warnings that @0xDEADCADE suggests are a nice addition before merging

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.