DOC: read_excel skiprows documentation matches read_csv (#36435)
- [x] closes #36435 
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

Updated `read_excel` documentation to match `read_csv` for the `skiprows` parameter.
Changed `test_read_excel_skiprows_list` to `test_read_excel_skiprows`: now also tests `read_excel` with an `int` and a `callable`. 
thanks @ahgamut .  Nice first contribution!