Corrects french translations

[Xav83]

Hi GoogleContactsEventsNotifier devs :slightly_smiling_face:

I am creating this Pull Request to help with the issue #118, during the Hacktoberfest, and help with the french translation.

So, in this Pull Request, I have reviewed the french translations, corrected some strings translation and made some french translations more accurate, in the file code.gs. :slightly_smiling_face:

[plainerman]

Thank you very much for your contribution! If you'd like to contribute more, any help is appreciated 😃 .

[Xav83]

@plainerman, by any chance, can you tag this Pull Request with the hacktoberfest label, in order to make it count in this year Hacktoberfest session ? :slightly_smiling_face:

[plainerman]

Is this sufficient?

[Xav83]

@plainerman , here are the information I have regarding the Hacktoberfest Pull Request requirements:

[plainerman]

I added the accepted label, but it says that it takes 7 days to be approved. If it does not work, you can get back to me.

[Xav83]

Thanks a lot @plainerman 🙂