DOC: timezone conversion example added to pandas.Series.astype doc #33399
…3399

- [x] closes #33399 

Have added an example in the documentation page of pandas.Series.astype for datetime type with timezone.
Hello @venkateshdatta1993! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:



There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2020-04-11 18:56:24 UTC Thanks @venkateshdatta1993!  > Thanks @venkateshdatta1993! 

Thanks @mroeschke for guiding me through this.