Expanded .gitignore support for popular OS's, text editors, etc

[plattthompson]

Ignores obtrusive or unnecessary files from the following:

• Most widely used operating systems
  • macOS (includes .DS_Store)
  • Windows
  • Linux
• Most popular text editors
  • VS Code
  • Sublime Text
  • Emacs
  • Vim
• Common front-end tools
  • Sass
  • Yarn
• React (in the event of a migration to Svelte)
  • Includes /node_modules
• Terraform & Terragrunt
  • For a simple deploy of your compiled files to an AWS S3
• Svelte
  • /public/build/

[Conduitry]

I'm strongly against this. This is a lot of stuff that people should either (a) put in their global gitignore if they're using the relevant text editors, or (b) should only add to their project's gitignore if they're using these libraries in their project. This is supposed to be a simple app template, and we don't want to be throwing every conceivable thing into the gitignore file, and then being forced to make future decisions about what to also add in, and also being forced to maintain this when some tools change their file naming schemes.