docs/readme.md: Added decpendency installation instructions

[zeGolem]

I don't know much about other distributions, feel free to add instructions if your distro isn't listed here :^)

[ElijahPepe]

Might be better if it links to https://go.dev/dl/.

[zeGolem]

I did consider that, though it doesn't have any real instructions for how to install it, it just hands you a .tar.gz, and even the install page doesn't give what I'd consider clear instructions…

Besides, on Linux, most people should probably be installing software through their package manager, unless manually installing it is the recommended way for go? Though I don't see a reason for that… I'm not a go developer, sorry…

I will probably link the official install docs too though, but keeping a simple copy-pastable command is probably a good thing for lesser-experienced users

[betapictoris]

Thank you, @zeGolem!