Add where people can find help if they want to contribute (#2415)
Add where people can find help if they want to contribute (#2415)

* Add where people can find help if they want to contribute

* Update CONTRIBUTING.md

Co-authored-by: Étienne Trimaille <7d2ca232957d746e2aa0f215f2e1dcf57eaa32e1@yahoo.fr>

Co-authored-by: Étienne Trimaille <7d2ca232957d746e2aa0f215f2e1dcf57eaa32e1@yahoo.fr>
rldhont/lizmap-web-client,nboisteault/lizmap-web-client,nboisteault/lizmap-web-client,3liz/lizmap-web-client,rldhont/lizmap-web-client,rldhont/lizmap-web-client,nboisteault/lizmap-web-client,nboisteault/lizmap-web-client,3liz/lizmap-web-client,laurentj/lizmap-web-client,3liz/lizmap-web-client,laurentj/lizmap-web-client,laurentj/lizmap-web-client,laurentj/lizmap-web-client,rldhont/lizmap-web-client,3liz/lizmap-web-client