Make Series.map() documentation a bit more verbose
Thanks for the quick response. I have added some text and added more code to be able to reproduce 'at home'. ## [Current coverage](https://codecov.io/gh/pandas-dev/pandas/pull/15235?src=pr) is 86.31% (diff: 100%)
> Merging [#15235](https://codecov.io/gh/pandas-dev/pandas/pull/15235?src=pr) into [master](https://codecov.io/gh/pandas-dev/pandas/branch/master?src=pr) will not change coverage

```diff
@@             master     #15235   diff @@
==========================================
  Files           139        139          
  Lines         51091      51091          
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
  Hits          44099      44099          
  Misses         6992       6992          
  Partials          0          0          
```

> Powered by [Codecov](https://codecov.io?src=pr). Last update [0c8442c...c5113f2](https://codecov.io/gh/pandas-dev/pandas/compare/0c8442c3f5c76c8e5b36ca313d3c38527e9f4b0c...c5113f2a15220c1935cbdf293eb89819a151e739?src=pr) thanks!