commit langref.html.in to source control instead of downloading it

[Techatrix]

#1409 was mistake

#2000 🎉

[nektro]

out of curiosity, why do you feel it was a mistake?

[Techatrix]

out of curiosity, why do you feel it was a mistake?

• various package distributions needed workarounds because the build phase can't just randomly access the internet
• the downloaded langref file is not properly cached which means that you can't build ZLS on the next day without internet
• the downloaded langref file is not pinned by commit hash which hurts reproducibility

ziglang/zig#17895 is the solution.

[nektro]

ah makes sense, i mistakenly assumed 17895 was already implemented

[BratishkaErik]

Thank you very much from GURU maintainer!