[c/fr] C French translation

[sun-exploit]

New C French translation c-fr.html.markdown file

• [x] I solemnly swear that this is all original content of which I am the original author
• [x] Pull request title is prepended with [language/lang-code]
• [x] Pull request touches only one file (or a set of logically related files with similar changes made)
• [x] Content changes are aimed at intermediate to experienced programmers (this is a poor format for explaining fundamental programming concepts)
• [x] If you've changed any part of the YAML Frontmatter, make sure it is formatted according to CONTRIBUTING.md
  • [x] Yes, I have double-checked quotes and field names!

[zethis]

Nice to have !

[verhovsky]

@vendethiel can you make the edits yourself and merge this please? You can do it from the browser if you click here

[vendethiel]

I think parts of this may have been machine translated. Fixed what I could and merged!