Adapt section references to order in document
Adapt section references to order in document

Summary:
Order of sections in INSTALLATION.md is:
I. Installation from binary packages on Ubuntu and ARM-based systems.
II. macOS installer
III. Windows installer
Adapt the order in the introduction. Closes T1501.

Test Plan: Review

Reviewers: MaxZ, pmaanen, hendrikk

Reviewed By: pmaanen

Maniphest Tasks: T1501

Differential Revision: https://dev.openmha.org/D541

HoerTech-gGmbH/openMHA,HoerTech-gGmbH/openMHA,HoerTech-gGmbH/openMHA,HoerTech-gGmbH/openMHA,HoerTech-gGmbH/openMHA,HoerTech-gGmbH/openMHA,HoerTech-gGmbH/openMHA,HoerTech-gGmbH/openMHA