Rewrite a correct Readme for the dev tools explaining the differents parts

Hello,

we need to explain all the different part of this repo and where is the development doc situated

Cheers

changed milestone to %FusionDirectory 1.4

added PJ1802-0188 label

assigned to @bmortier

created branch 44-rewrite-a-correct-readme-for-the-dev-tools-explaining-the-differents-parts to address this issue

closed via commit 740404e6