Run Prettier across projects

Problem:
Prettier was not running when I saved Emacs buffers.

Why?
- prettier-js-mode needs needs node; lorri exposes node to direnv; direnv
  exposes node to Emacs; lorri was not working as expected.

Solution:
Now that I'm using nix-buffer, I can properly expose node (and other
dependencies) to my Emacs buffers. Now Prettier is working.

Commentary:
Since prettier hadn't worked for so long, I stopped thinking about it. As such,
I did not include it as a dependency in boilerplate/typescript. I added it
now. I retroactively ran prettier across a few of my frontend projects to unify
the code styling.

I may need to run...
```shell
$ cd ~/briefcase
$ nix-shell
$ npx prettier --list-different "**/*.{js,ts,jsx,tsx,html,css,json}"
```
...to see which files I should have formatted.

website/goals/package.json

@@ -4,11 +4,13 @@
   "main": "index.js",
   "license": "MIT",
   "scripts": {
-    "dev": "npx parcel src/index.html & npx tsc --watch --noEmit"
+    "dev": "parcel src/index.html & npx tsc --watch --noEmit",
+    "prettier": "prettier --ignore-path .gitignore --write \"**/*.{js,ts,jsx,tsx,html,css.json}\""
   },
   "devDependencies": {
     "@types/node": "^13.9.3",
     "parcel-bundler": "^1.12.4",
+    "prettier": "^2.0.2",
     "tailwindcss": "^1.2.0",
     "typescript": "^3.8.3"
   },