Spotifycl

Just some quick UI changes/fixes!

>>> spotifycl.__license__
'MIT'

In this release, I first added color to every output to the terminal. I also switched out [termcolor](https://github.com/termcolor/termcolor) with [rich](https://github.com/Textualize/rich), since it's much more widely used, and has a better print function in my opinion.

In previous releases, spotifyCL would generate the `.cache` file in whatever directory the terminal session was currently in. This was terrible for obvious reasons, such as polluting random directories with `.cache` files or re-authenticating every time one switched directories. To fix this, I set the cache_path as the directory of spotifyCL, so it's completely out of sight, out of mind!

This release just adds [NumPy/SciPy Docstrings](https://numpydoc.readthedocs.io/en/latest/format.html) to the code. I also fixed some return statements that gave an error on my [ohmyzsh](https://github.com/ohmyzsh/ohmyzsh) console.

This is a fairly simple release. I just added some error handling to check if there's a current Spotify session going on, since if there wasn't it used to generate huge error messages. It now has a simple error message as opposed to the previous line of text. Some error messages are automatically printed by the [Spotipy Package](https://github.com/spotipy-dev/spotipy), while others are handwritten by me. I'd rather them all be handwritten since the end user doesn't need to know about HTTP Requests, but I really don't feel like muddling around with Spotipy.