Add more detailed tool explanations

[Zethson]

Fixes #474

[codecov[bot]]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (a98cb3d) 64.07% compared to head (b9f14d8) 64.07%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #528 +/- ## ======================================= Coverage 64.07% 64.07% ======================================= Files 43 43 Lines 4982 4982 ======================================= Hits 3192 3192 Misses 1790 1790 ``` | [Files](https://app.codecov.io/gh/theislab/pertpy/pull/528?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=theislab) | Coverage Δ | | |---|---|---| | [pertpy/tools/\_coda/\_tasccoda.py](https://app.codecov.io/gh/theislab/pertpy/pull/528?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=theislab#diff-cGVydHB5L3Rvb2xzL19jb2RhL190YXNjY29kYS5weQ==) | `77.48% <0.00%> (ø)` | | | [pertpy/tools/\_coda/\_base\_coda.py](https://app.codecov.io/gh/theislab/pertpy/pull/528?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=theislab#diff-cGVydHB5L3Rvb2xzL19jb2RhL19iYXNlX2NvZGEucHk=) | `56.08% <0.00%> (ø)` | |