Create a feature map to understand what are the features that need documentation

[hbelmiro]

Now that we have a solid structure in place we should start building a "feature map" to understand the features that need documentation, the ones that are already documented but need improvement, and the green ones. We can do a table like this:

Feature	Status	Type
feat A	Missing	User guide
feat A	Partial	Reference
feat B	Done	User guide
feat B	Missing	Reference

Depends on: #3737
More context: #3737 (comment)

[hbelmiro]

/area pipelines