ValveSoftware/Proton ? reverse-engineered prompt

Help me build and install a local version of Proton from this repo so I can try it in Steam on Linux.

I want a simple setup that follows the README, uses the container based build if needed, and ends with something I can drop into my Steam compatibility tools folder or install with the provided make target. If there are missing dependencies or a better way to do it on my machine, please point that out and fix the setup so it works cleanly. If you need to look up current docs online, go ahead.

Also, if there is a reasonable default way to rename the build so it shows up clearly in Steam, include that. I’d like the final result to be easy to rebuild later too, not just a one off build.