[docs] Services documentation

Summary:
Services building, configuration, and running documentation (GitHub).

Related linear task: ENG-669

Test Plan: No tests for markdown.

Reviewers: karol-bisztyga, palys-swm, jimpo, geekbrother, ashoat

Reviewed By: karol-bisztyga, palys-swm, geekbrother, ashoat

Subscribers: benschac, ashoat, palys-swm, Adrian, atul, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D3240