docs(contributing): Use squash instead of rebase
docs(contributing): Use squash instead of rebase

I think what we want to say is that we should squash commits together
to remove the unnecessary and temporary commits before accepting the
PR. We still use rebase when keeping in sync with develop.

algolia/instantsearch.js,algolia/react-instantsearch,algolia/react-instantsearch,algolia/instantsearch.js,algolia/instantsearch.js,algolia/react-instantsearch,algolia/react-instantsearch