Add a blurb about Debian being explicitly and intentionally minimal

Also, add more notes and a few links to help explain what "minimal" means in this context (and who decides it).

Author: tianon

debian/content.md

@@ -8,6 +8,8 @@ Debian is an operating system which is composed primarily of free and open-sourc
 
 # About this image
 
+The images in this repository are intended to be as minimal as possible (because of the immutable/layered nature of containers, it's much easier to add than it is to remove). More specifically, they're built from [the "minbase" variant](https://manpages.debian.org/stable/debootstrap/debootstrap.8.en.html#variant=minbase_buildd_fakechroot), which only installs "required" packages, and thus creates the smallest possible footprint that is still "Debian" (as defined/managed by [the Release and FTP teams](https://www.debian.org/intro/organization#distribution) within the project).
+
 The `%%IMAGE%%:latest` tag will always point the latest stable release. Stable releases are also tagged with their version (ie, `%%IMAGE%%:11` is an alias for `%%IMAGE%%:bullseye`, `%%IMAGE%%:10` is an alias for `%%IMAGE%%:buster`, etc).
 
 The rolling tags (`%%IMAGE%%:stable`, `%%IMAGE%%:testing`, etc) use the rolling suite names in their `/etc/apt/sources.list` file (ie, `deb http://deb.debian.org/debian testing main`).