Expand snap description and remove comments
Expand snap description and remove comments

This commit removes the boilerplate comments that come with the template snapcraft.yaml. It also expand the description to match the project's README.
jwilm/alacritty,alacritty/alacritty,alacritty/alacritty,jwilm/alacritty,jwilm/alacritty,jwilm/alacritty