[New Check]: TimeSeries rate is zero

[alessandratrapani]

Related to Issue #389
Add a check function to check if the sampling rate is set to 0.0Hz

• add check function
• add unit tests
• add check function documentation
• update CHANGELOG.md

[CodyCBakerPhD]

A couple things here:

(i) need unit tests

(ii) It occurs to me that for all of these PRs, you will have to run pre-commit manually since the bot does not work when the contributor is technically a GitHub organization (weird edge case with permissions that no one seems to be able to figure out - external forks are fine whenever they are an individual rather than an organization)

It's very simple though

pip install pre-commit
pre-commit install
pre-commit run -a

from a terminal while inside your clone of the CN fork of the repo

[CodyCBakerPhD]

This looks good, just need a changelog entry (also if you approve #406 I can merge that in first so it can always be there to flag it on PRs)

[bendichter]

congratulations @alessandratrapani on your first contribution!