To install the config, copy init.lua to ~/.config/nvim/init.lua
if ~/.config/nvim/ doesnt exist just make a new folder
Ctrl + f Focus on file tree
Ctrl + t Toggle file tree
Ctrl + k Search for files
Ctrl + s Save File
To use the nvim config with godot, go to editor settings and find the option called "Editor" under "Dotnet".
Set the external editor to "Custom", the "Custom Exec Path" to nvim or whatever your neovim binary is called. Then put --server /tmp/godot.pipe --remote-send "<esc>:n {file}<CR>:call cursor({line},{col})<CR>"
in the "Custom Exec Path Args" textbox.
Now restart godot and doubleclick your script. Then open your script with neovim and it should work. This supports GDScript and C#.