Broken "many checks" link in validation chapter

[jorgepiloto]

🐞 Problem

In section Docstring Validation during Sphinx Build, the following paragraph contains a broken link, see:

The complete validation suite contains many checks including some for style, capitalization, and grammar. It is unlikely that reporting all validation warnings is desirable for most use-cases. Individual checks can be excluded by including them in the set with the special keyword "all":

It should point to Built-in Validation Checks, just the section below.

[rossbar]

Thanks for reporting @jorgepiloto !