Change the projects listed on the homepage

[TonioGela]

@valencik nerd-sniped me, this PR it's the outcome.

If we want to change the listed projects it's enough to pick different ones in the names array

{% assign names = "Cats|Cats-Effect|fs2|http4s" | split: "|" %}

The values must correspond to titles in the projects data

I'll say that either four or six projects is the perfect number to show on the home

[TonioGela]

[valencik]

Thanks for this!

How do you feel about cleaning up the lingering core: true annotations in the project data file as part of this PR? For example: https://github.com/typelevel/typelevel.github.com/blob/4e1d42f2aa5a54399bb5d9b2089265cc8d96dd4b/_data/projects.yml#L33

[SethTisue]

👏