Symspellpy

- Fixed `lookup_compound()` to return the correct `distance`

- Added `<self._replaced_words = dict()>` to track number of misspelled words
- Added `ignore_token` to `word_segmentation()` to ignore words with regular expression

- Added `word_segmentation()` feature

- Added `encoding` option to `load_dictionary()`

- Create a package for `symspellpy`

- Ported [SymSpell](https://github.com/wolfgarbe/SymSpell) v6.3