rewrote the new branch feature page

Hello,

we need to rewrite the new branch feature page

https://fusiondirectory-developer-documentation.readthedocs.io/en/1.4/releasing/new-feature-branch.html

to have more usefull explanations and separated by software

Cheers

changed milestone to %FusionDirectory 1.4

added PJ2003-0343 label

assigned to @bmortier

created branch 73-rewrote-the-new-branch-feature-page to address this issue

mentioned in commit 9a28e015

added Added label