Ripgrep: searching with negative lookahead

Using [ripgrep](https://github.com/BurntSushi/ripgrep) we can search using PCREs. First we need to enable pcre expressions in `~/.ripgreprc`:
```
--pcre2
```
Then we can search for all occurences of `myword` **not** followed by `_`:
```
> rg 'myword(?!_)'
```

alexanderpresber
December 14, 2021