Restructure landing page

[ddundo]

In #52 (comment)_ we agreed to make https://mesh-adaptation.github.io/ a static landing page that would link to https://mesh-adaptation.github.io/docs, which are now automatically built and deployed. So we need to update https://mesh-adaptation.github.io/ accordingly.

So the website tree would then look something like

https://mesh-adaptation.github.io/
    ├─ docs/
    │  ├─ animate
    │  ├─ goalie
    │  ├─ movement
    │  └─ UM2N
    ├─ papers
    └─ ...

Or docs/papers etc.

[ddundo]

@jwallwork23 in mesh-adaptation/mesh-adaptation.github.io@ffc784b I left everything as it is but just redirected all links to the new build at https://mesh-adaptation.github.io/docs/ now, so that we'd have working references etc.

[joewallwork]

@jwallwork23 in mesh-adaptation/mesh-adaptation.github.io@ffc784b I left everything as it is but just redirected all links to the new build at https://mesh-adaptation.github.io/docs/ now, so that we'd have working references etc.

Nice - that works for the time being.

For the landing page it'd be great to have four clickable boxes with the name of the package and its logo in it, where clicking is a link the appropriate part of the docs. Of course, we don't currently have any logos, so just the letter "A", "G", M", or "U" would be sufficient for now.