chapter 2's introduction hackable French translation

[FlorentFlament]

In this context, the word "hackable" doesn't translate in "piratable" (which conveys the notion of illegal piracy). I believe that "modifiable" (i.e can be modified) is more appropriate.

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.