Collect PM oriented Learning and Development materials

Following on: #1986 (comment 492104550)

L&D: there are ad-hoc possiblities, and as already collected by Patrick, LinkedIn Learning won't solve this. I think that many of us knows its own shortcomings (in my case: English and financials). Still, I'm on my own (not true, @kbychu supports me a lot :)) to come up with trainings in these areas. Thinking about the various initiatives we went through the past year, I can imagine that some PMs might miss data-related trainings, I continuously hear from UX how great my user interviews are, thus it might happen that others would need trainings there too, and in general around discovery, my personal perception is that we could be much-much stronger. In this respect, we've had a single organized Continuous Interview course, and otherwise we don't have much content in the handbook about where to look for trainings. As I wrote these down, I volunteer to put together such a page.

Idea

Link from each row of https://about.gitlab.com/handbook/product/product-manager-role/#product-management-career-development-framework to the corresponding section of a PM L&D page

For each section the page should contain:

• might contain multiple frameworks/topics (e.g: JTBD, interviews)
• for each topic
  • max 3 books
  • introductory youtube videos
  • links to recommended deep dive course (1-2)
  • optionally a PM or other person inside GitLab who offers mentorship