Change the return value of `notify()` (as already mentioned in documentation)

[benjaoming]

• More tests! :taco:
• More documentation! :tada:
• Return a list of notifications in the notify function, but I will consider how that scales before releasing it... or maybe add a faster alternative.
• Correct disable_notify since it was broken :(
• Remove un-implemented setting :(

[codecov[bot]]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (08571fc) 74.87% compared to head (91e3fcc) 76.73%.

Files	Patch %	Lines
django_nyt/utils.py	85.71%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #134 +/- ## ========================================== + Coverage 74.87% 76.73% +1.85% ========================================== Files 23 23 Lines 621 619 -2 ========================================== + Hits 465 475 +10 + Misses 156 144 -12 ```

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[benjaoming]

This is moving along nicely, making a pre-release after merging this in order to try it out :+1:

[benjaoming]

Any input well-received!