feat: README cleanup

Our FAQ & Troubleshooting section is getting fairly large.

Let's follow the pattern in brew's repo with a main [TROUBLESHOOTING.md](https://github.com/Homebrew/brew/blob/master/docs/Troubleshooting.md) and [COMMON-ISSUES.md](https://github.com/Homebrew/brew/blob/master/docs/Common-Issues.md) doc

There are also some other cleanup actions we can perform to make things a little more hospitable to our users.

```[tasklist]
### Tasks
- [ ] Create table of contents
- [ ] clean up troubleshooting & faq section according to conclusions we come to on this issue.
```

### Questions/Concerns:

1. If we update troubleshooting to a new document, some existing links in issues (open and closed) will break. Are we okay with this?
2. If we don't want to move troubleshooting/faq, how else can we clean things up?