[docs] Add tldr section for coredb contributors

[jaki]

CoreDB contributor docs for compiling have separate pieces of instructions with some beneficial commentary, but there is no fast way to do it in one shot.

Add a tldr section for all the linux platforms that collects all the separate instructions into one place. This means future edits to the instructions may need to worry about keeping the two in sync, but the convenience seems worth it. Tested using docker images centos:7, ubuntu:20.04, ubuntu:22.04, almalinux/8-minimal. It would be nice to create docker files using those images as a followup.