Add a link to TOC in client-add-dev.md
Add a link to TOC in client-add-dev.md

nono/cozy-stack,sebn/cozy-stack,sebn/cozy-stack,nono/cozy-stack,sebn/cozy-stack,nono/cozy-stack,sebn/cozy-stack,nono/cozy-stack,nono/cozy-stack