Snap: create apt/deb, snap comparison table

Create a table of features to compare deb package management capabilities with snap package management.

Background

This is a table that has been requested by many different people. It's purpose isn't to say one packaging scheme is better than another, but rather to show a comparison of their capabilities side-by-side.

An overview of snap's most important features can be found here: https://snapcraft.io/docs/quickstart-tour

Prerequisites

You will need some experience with snap and deb packages, and how they're installed and maintained.

See also Contribute to our documentation.