Switching from 2.0 Beta to Stable 2.0

[bilgeyucel]

• Switch tutorial overview pages

  • https://haystack.deepset.ai/tutorials and https://haystack.deepset.ai/tutorials?v=2.0 should display 2.0 tutorials with the current banner
    

  • https://haystack.deepset.ai/tutorials?v=1.0 should display 1.x tutorials (tutorials that dont have haystack_2 = true)

• All 2.0-beta tags should be 2.0

  • "Haystack version" dropdown options should be 1.0 and 2.0 (not 2.0-beta)
  • Tags above "Tutorials" and "Documentation" should be 2.0
  • Tutorial sidebar tags should be 2.0
  • Tutorial cards should have 2.0 tag with a star icon (or any relevant icon), not 2.0-beta
    

• Remove 1.x tutorials from the sidebar (tutorials that dont have haystack_2 = true) and only display 2.0 tutorials
  

[TuanaCelik]

I've resolved the second point in the #304 PR, the first and third I leave to @carlosgauci

[carlosgauci]

Also resolved the other points in the PR :)