Is your feature request related to a problem? Please describe.
Currently, tutorials are sorted by values in the .yml file - first on the level and then alphabetically by the name. We need a better way of sorting the tutorials so that specific tutorials are ordered with a higher priority and the rest can be sorted alphabetically. The filters should be visible by default.

Describe the solution you'd like
The filter list should be on by default not closed as in this image:

So it should look like this:

We need a new property in each tutorial's .yml file that specifies the priority.
The first sorting will be on the levelproperty - as it currently is. The for the display order of tutorials with the same level we need a new property called priority. The priority property should be able to handle a 3 digit number so that the if a new tutorial is added it could easily after or before an existing one.

If a tutorial doesn't have a priority, it goes at the end ordered alphabetically by the name property in the .yml file.
If 2 tutorials have the same priority, between them they are then ordered alphabetically by the name property in the .yml file.

Describe alternatives you've considered
Another approach is https://ethereum.org/developers/tutorials/
But Remix tutorials should come first in each level

The other issues is that we only have a column in LearnEth - so the ethereum.org approach won't work. But we also need to make the tag system more robust.