French translation - Missing changes from last PR - Lesson 2.2 (#340)

* - Added README.fr.md in the root folder
- Translated the whole leçon 2.1 <predict plant growth>

* just added the whole content

* small updates in root folder

* Unnecessary shields removed and some corrections have been made from Charles's review

* Translation of all lessons of the root README

* Translation of for-teachers.md

* Translation of hardware.md

* Translation of CODE_OF_CONDUCT.md

* Translation of CODE_OF_CONDUCT.md

* Implement suggested changes from the charles's PR review

* Implement suggested changes from the charles's PR review

* Implement suggested changes from the charles's PR review

* Implement suggested changes from the charles's PR review

* Changed the path to the translated README because they were not working from the translated ones

* Small change

* Resolved unworking links in hardware.fr.md

* Removed the shields where it was not necessary as Jim suggested

* small correction

* Removed the shields and comments as requested by Jim

* small update

* Small correction on root README

* farm > lesson 2 > assignement.fr.md

* farm > 2 > README.fr.md

* pi-soil-moisture.fr.md completed

* farm > lesson 2 > virtual-device-soil-moisture.fr.md

* farm > lesson 2 > wio-terminal-soil-moisture.fr.md

* Update README.fr.md

* Corrected a non functionnal .md link

Co-authored-by: Jim Bennett <jim.bennett@microsoft.com>

2-farm/lessons/2-detect-soil-moisture/translations/README.fr.md

@@ -20,7 +20,7 @@ Dans cette leçon, nous aborderons:
 
 * [Humidité du sol](#humidité-du-sol)
 * [Comment les senseurs communiquent avec les composants IoT](#comment-les-senseurs-communiquent-avec-les-composants-IoT)
-* [Mesurer les niveaux d'humidité dans le sol](#mesurer-les-niveaux-d'humidité-dans-le-sol)
+* [Mesurer les niveaux d'humidité dans le sol](#mesurer-les-niveaux-d-humidité-dans-le-sol)
 * [Étalonnage du capteur](#étalonnage-du-capteur)
 
 ## Humidité du sol