Translate contribute.md in french
Update contribute.md
Translate install-linux.md in french
orthographe
Update install-linux.md

traduction française
Update install-linux.md
Update tutorial-converting.md
Merge pull request #221 from VincentGaribal/master

french translation of contribute.md
Translate 'folder' to 'dossier' in French
Web site: French translation of Sozi conversion tutorial
Merge branch 'lebendre-master'
Web site: conversion tools are available in the master branch
Merge branch 'master' into dev