Docs Arrow version selector

[AntonioMateoGomez]

This PR closes #1309

That's how it would look. We have incorporated an information bar that highlights the version of the library in which we are. At the moment in which the user closes it, you will no longer appear. We do not want it to be a nuisance.

We have chosen to give importance to the middle button (stable version) in the masthead using the highlight of colors instead of changing its size so that the design continues having a better disposition

[pakoito]

Do we only want to keep 3 versions?

[AntonioMateoGomez]

We will keep all the versions, but the top bar and the buttons will show just PREVIOUS, STABLE and NEXT . Clicking in documentation in the nav bar will show all the versions, we have got the same in the docs sidebar.

The oldest versions will appear below the 3 that are shown in the screenshot as It shows below. V.0.1.0 and v.0.2.0 are not real data, it is just to have an idea of how it will look like.

[pakoito]

thanks!

[JorgeCastilloPrz]

Great job 👏👏👏

[pakoito]

If it's all green I'm happy for it to be sent for review and stamp it!

[calvellido]

Sidebar dropdown button doesn't fill the sidebar width completely, which creates a weird effect when the rest of elements in the sidebar do.

@israelperezglez what's your take on this?

[raulraja]

@calvellido @AntonioMateoGomez merge at will when this is ready to go

[calvellido]

🚀