Rework grammar inflection parsing

[radomirbosak]

See changed docs:

• README.md
• CHANGELOG.md
• usage.md

Fixes: #156

TODO:

• Documentation
• Fix code style
• Changelog
• Consider renaming Grammar to Inflection
• Export inflection enums to base package (from duden import Case, Person, Mood)
• Remove grammar
  • Remove/deprecate functions
  • Remove documentation
  • Remove/deprecate CLI --grammar
  • Remove from tests
  • remove constants
• Inflect
  • Add functions
  • Add CLI option
  • Add documentation
  • Add tests

TODO in later PR:

• --inflect CLI option
  • allow specifying subkeys -> see Allow getting individual inflection forms via CLI #193
  • colorize keys -> see Allow getting individual inflection forms via CLI #193
  • provide guidance / help messages -> see Allow getting individual inflection forms via CLI #193
• split Person Enum and rewrite ImperativePerson enum -> see Allow getting individual inflection forms via CLI #193

Usage

module

> inf = get("Hase").inflection
> inf
(Inflector: 'der Hase', ...)

> inf.data
{'Deklination': {'Singular': {'Nominativ': 'der Hase',
   'Akkusativ': 'den Hasen',
   'Dativ': 'dem Hasen',
   'Genitiv': 'des Hasen'},
  'Plural': {'Nominativ': 'die Hasen',
   'Akkusativ': 'die Hasen',
   'Dativ': 'den Hasen',
   'Genitiv': 'der Hasen'}}}

> inf.noun_decline(Number.SINGULAR, Case.DATIVE)
'dem Hasen'

> inf.noun_decline(Number.SINGULAR, "Kusative")
ValueError: Cannot inflect. Missing data for: 'Deklination'.'Singular'.'Kusative' . Did you mean 'Nominativ', 'Akkusativ', 'Dativ', 'Genitiv'?

CLI

$ duden Hase --inflect
Deklination:
  Plural:
    Akkusativ: die Hasen
    Dativ: den Hasen
    Genitiv: der Hasen
    Nominativ: die Hasen
  Singular:
    Akkusativ: den Hasen
    Dativ: dem Hasen
    Genitiv: des Hasen
    Nominativ: der Hase

[radomirbosak]

Even if this is not finished, I need to merge this so that the project is not slowed down further. Unfinished parts will be fixed by subsequent MRs.

[radomirbosak]

Created a new issue for TODO: #193

[radomirbosak]

Remove/deprecate functions

This point was promoted to an issue #194

[radomirbosak]

Released in 0.19.0 🎉