Add option to filter assets

[jakebellacera]

It'd be nice to exclude assets based off of filename, path, etc. For instance, we don't need to include assets from CSS into the manifest.

Describe the solution you'd like
An option to filter assets based off of path, name, etc:

new AssetsPlugin({
  exclude: ({ path }) => /src\/scss/.test(path)
});

[ztoben]

For now you could use the fileTypes option, but I agree that having some kind of regex match would be a nice feature. Thanks for the suggestion.