Creating a new Rails app with nix and devenv

creating_rails_app.md

1. mkdir hello_world
2. cd hello_world
3. devenv init
4. devenv inputs add nixpkgs-ruby github:bobvanderlinden/nixpkgs-ruby --follows nixpkgs
5. direnv allow .
6. echo ruby-3.3.6 > .ruby-version (use most recent version of Ruby)
7. Change the content of devenv.nix to:

   { pkgs, lib, config, inputs, ... }:
   
   {
     packages = [ pkgs.git pkgs.foreman pkgs.libyaml.dev ];
   
     languages.javascript = {
       enable = true;
       npm.enable = true;
     };
   
     languages.ruby = {
       enable = true;
       versionFile = ./.ruby-version;
     };
   }

8. gem install rails
9. cd .. && cd - (otherwise the newly-installed rails will not be in the path)
10. THOR_MERGE="nvim -d" rails new -c tailwind .
11. Choose to merge .gitignore and any other files
12. Copy content of temporary file into the file in the directory (such as .gitignore)