Adds french translation for curl rest api guide

[ArnolFokam]

Description

I have translated the How to use curl to test a REST API into french. Here are some keynotes of my work:

• I changed keyboard word Enter to Entrée as that's what is written on most french keyboards (AZERTY)
• I did not translate code especially those representing JSON data so that it could match what was on the images/GIFs.
• Jekyll properly served the page.
• I had no strange validation errors from AMP apart from the ones noticed in my last pull request #87

Fixes #70

Required checklist:

• [x] My code matches the existing code style of this project.
• One of these:
  • [ ] This is a new localization for existing content.
  • [ ] This is new content that is localized for all the locales that this project currently supports.
  • [x] I described above how I plan to localize this content immediately after merging these changes.
  • [ ] Localization is not applicable to this change.
• [x] I have tested my code and it successfully builds for GitHub Pages and validates as AMP.

[ArnolFokam]

Looks good to me. Fantastic translation! I really appreciate your detailed approach, such as the use of Entrée to match and the image alt attribute translations :) Thanks again for validating locally as well.

You're welcome @devadvance :) If there is a need for further work on this FR translation. Just notify me.