`proc-macro derive panicked: message: not yet implemented`

[Grammar I tried to load](https://github.com/rscarson/lavendeux-parser2/blob/master/src/grammar.pest)

Tried removing the `ASCII_DIGIT{1,3}` in case it was related to [this todo!()](https://github.com/Mubelotix/faster-pest/blob/4394ff4208d25ac12861993b99fff722e1b88192/faster-pest-derive/src/optimizer.rs#L118)