add forge section in the course

docs/pages/git/git-forge.md

+<iframe id="iframepdf" src="../git-forge/01_forge_ird.html" frameborder="0" width="1280" height="768" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true">
+</iframe> 

mkdocs.yml

@@ -100,7 +100,7 @@ nav:
         - Tagging commits: pages/git/git-6-tags.md
         - Working remotly: pages/git/git-7-working-remotely.md
         - Conflict: pages/git/git-8-conflicts.md
-        - La forge IRD: pages/git/git-7-forge-ird.md
+        - La forge IRD: pages/git/git-forge.md
         - Graphical Interface:
             - RStudio: pages/git/git-9-rstudio.md
             - VScode: pages/git/git-9-vscode.md