Adding more documentation for upsampling with replacement and error m…
…essage in case replacement is set to False

- [X] closes #27451
- [x] tests added / passed
- [X] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

Hello @CooperData! 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 2019-11-07 23:38:05 UTC lgtm. ping on green. @jreback - CI failed but I am not sure what it's causing the issue. I was able to run the tests while I was at the sprint. But dont know if I did anything that is creating the issue. see https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=20307&view=logs&jobId=d6a36677-9147-59f9-684d-001fc5c44c5e

looks like just some extra white space 

fix and push up if u can  I added a dot at the end of the raised error as per other errors I saw. I also changed the test msg checked to match the error raised so it's 2 lines as well. I was not able to understand what exactly the error was. thanks @CooperData  @jreback, I am going through the messages on the build for the last push, and it seems it's failing because the function inside that is supposed to give the error message is failing. In other words, the desired behavior is to make the test fail but compare the error message, not to make the test fail itself.  The failures seem associated with something else that I did not change: [errors](https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=20397&view=logs&jobId=5ddd427e-1f95-5998-4195-7ffbeb9b114d&taskId=607906cd-31fb-52fc-bb5f-740f55a1afa6&lineStart=150&lineEnd=186&colStart=1&colEnd=126)
 thanks @CooperData !