README french version.

[KaGaster]

Hello.
A french friend of mine is interested in contributing in this project. When I read the french version of README file, I have spotted some minor mistakes and some important phrases missing(The two first phrases specifying the need of bug fixes over features proposition). If you don't mind, I can fix it and send it to you before today 5 pm.

[TobiGr]

Thanks, go ahead :)

[KaGaster]

Hello.
Here is the proposed new version below.
Let me know your thoughts on it.

Thank you in advance.

README.fr.md

[TobiGr]

Please open a PR

[KaGaster]

Here you go