Add additional clarifying details to documentation guide (in developer's guide)

[RNKuhns]

Reference Issues/PRs

Relates to #1245

What does this implement/fix? Explain your changes.

Based on feedback during the docsprint, I've included clarifying content to the documentation portion of the developer guide.

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

Are the added clarifying details clear enough that developers can easily follow them?
Are there other areas where clarification is needed?

What should a reviewer concentrate their feedback on?

Any other comments?

PR checklist

For all contributions

• I've added myself to the list of contributors.
• Optionally, I've updated sktime's CODEOWNERS to receive notifications about future changes to these files.
• I've added unit tests and made sure they pass locally.

For new estimators

• I've added the estimator to the online documentation.
• I've updated the existing example notebooks or provided a new one to showcase how my estimator works.

[RNKuhns]

Ignore the boxcox.py change, that was meant to be separate (see #1314).

@GuzalBulatova, @SveaMeyer13, @Lovkush-A and @aiwalter can you look at the read the docs build from this PR and let me know if:

• The new clarifications (e.g. how to do cross-references, etc) are clear
• Whether you think there are other areas clarifications that would be useful

[Lovkush-A]

I like the extra information included. Suggestions are:

• typos
• slight rewordings which i think are clearer or more concise
• inclusion of good examples section

[Lovkush-A]

Typos outside of changes in this PR (and so I cannot suggest directly in the code...)

Line 14. api_refernce
Line 22. The url does not become a hyperlink

[RNKuhns]

Typos outside of changes in this PR (and so I cannot suggest directly in the code...)

Line 14. api_refernce
Line 22. The url does not become a hyperlink

Thanks for pointing those out. I'll push a commit to fix them.

[Lovkush-A]

looks good! (note that in contractbleBOSS, the joint reference [1,2] did not become a hyperlink)

[RNKuhns]

@Lovkush-A thanks for taking a look and approving. Do you mind opening a PR to fix the link rendering in ContractableBoss?

[Lovkush-A]

Do you mind opening a PR to fix the link rendering in ContractableBoss?

I can do it in my PR in which I am updating three or four other docstrings. I think I read the CI/CD system is strugging and that having fewer PRs should help.

[RNKuhns]

@mloning are you fine if we merge this since it only affects docs?

[mloning]

Yes, this has been reviewed so happy for this to go in

[mloning]

Now merged - thanks @RNKuhns!