Unify concepts between articles and courses

[andreilgeorgescu]

While working on #202, I came to the conclusion that there are a few things that can be unified between articles and courses:

• Tags
  • Can refer to technologies and concepts used (ex: Scala, Functional Programming, ZIO)
• Published Date
• Updated Date
• Authors
  • Course author(s)

Adding these could improve the quality of search results. What do you think?