[DOC ] Added examples to docstrings for K-Means and K-Medoids

[CTFallon]

Reference Issues/PRs

Adds to #4264.

What does this implement/fix? Explain your changes.

Added usage examples to k_means and k_medoids.

Does your contribution introduce a new dependency? If yes, which one?

No.

What should a reviewer concentrate their feedback on?

Did you add any tests for the change?

No.

Any other comments?

PR checklist

For all contributions

• I've added myself to the list of contributors with any new badges I've earned :-)
  How to: add yourself to the all-contributors file in the sktime root directory (not the CONTRIBUTORS.md). Common badges: code - fixing a bug, or adding code logic. doc - writing or improving documentation or docstrings. bug - reporting or diagnosing a bug (get this plus code if you also fixed the bug in the PR).maintenance - CI, test framework, release.
  See here for full badge reference
• Optionally, I've added myself and possibly others to the CODEOWNERS file - do this if you want to become the owner or maintainer of an estimator you added.
  See here for further details on the algorithm maintainer role.
• The PR title starts with either [ENH], [MNT], [DOC], or [BUG]. [BUG] - bugfix, [MNT] - CI, test framework, [ENH] - adding or improving code, [DOC] - writing or improving documentation or docstrings.

For new estimators

• I've added the estimator to the API reference - in docs/source/api_reference/taskname.rst, follow the pattern.
• I've added one or more illustrative usage examples to the docstring, in a pydocstyle compliant Examples section.
• If the estimator relies on a soft dependency, I've set the python_dependencies tag and ensured
  dependency isolation, see the estimator dependencies guide.

[fkiraly]

Welcome to sktime, and thanks for your contribution!

The examples are great, although there's a small dependency management issue: the estimators depend on numba, so the doctest should be skipped, using the +SKIP directive (search for that in the code base for examples, and please let us know if it's not clear what I'm asking for)

The reason being, the examples are executed as tests otherwise, even if the dependency is not installed, that would raise an error.

[fkiraly]

Thanks, should be all good now! Let's see that tests pass.

[CTFallon]

Pulled from main after the Yoga/UEA fix (#4741)