Allow customising watchers via options.#46

Hey, this is a great tool! We've recently moved our repo to turborepo and are just configuring turbowatch to retain some of the good DX we used to have (typecheck, lint watch..) However, we found that when turbowatch starts, `chokidar` begins indexing files and, due to how our monorepo is set up and the dependencies between packages (there might be a cycle somewhere), `chokidar` never stops indexing the files inside `node_modules`. It keeps following symlinks recursively. You can see in the logs how the number of indexed files grows infinitely to the millions. `chokidar` specifically allows you to provide some glob patterns of files that will be ignored (via the `ignored` param). Is this something the library could support? Currently we're working around this by providing a custom `Watcher` which is exactly the same as your `ChokidarWatcher` but it creates the `chokidar` instance with an additional `ignored` parameter: An alternative to this would be to adapt the glob expression provided to `turbowatch` to the `ignored` glob chokidar accepts, which would be more efficient than scanning all files to then 'discard' most of them. ``` this.chokidar = chokidar.watch(project, { ignored: ['**/node_modules/**'], awaitWriteFinish: false, followSymlinks: true, }); ``` We can stick to this but it'd be great if we were able to just pass some of `WatchOptions` (from `chokidar`) instead of a whole new `WatcherConstructable`. What do you think? I'm happy to contribute.