Ckipnlp

- [Docs] Add NER Tags.
- [Docs] Update parser registry URL.

- Add username & password options to `CkipClassicConParserClient`.

- Fix typo in PyPI's classifiers.

- Update license to GPL-3.0
- Update documentation.

- Add support to classic parser client (now supports CKIPParser academic license). [23]
- Require CkipTagger 0.2.1 or above (now supports TensorFlow 2+).

- Name changes:
- Rename `CkipClassicConstituencyParser` to `CkipClassicConParser`.
- Rename `constituency` to `conparse` in `CkipPipeline`, `CkipDocument `, `CkipCorefPipeline` and `CkipCorefDocument`.
- Rename `get_constituency` to `get_conparse` in `CkipPipeline`, `CkipCorefPipeline`.
- Rename `constituency_parser` to `con_parser ` in `CkipPipeline`, `CkipCorefPipeline`.
- Rename `ckipnlp.data.constituency` to `ckipnlp.data.conparse`.

- Bug fixes:
- Not segment clauses by `PAUSECATEGORY` in ClassicConstituencyParser. [27]