Update for Ensmallen / Embiggen -> grape

[caufieldjh]

• [x] Where previously installing ensmallen and embiggen, install grape
• [x] Update imports and methods to refer to grape, e.g. from grape.embedders import SkipGramEnsmallen
• [ ] Update for grape native methods as per #77

See the grape tutorials for examples: https://github.com/AnacletoLAB/grape/tree/main/tutorials