Suggestions interface

The suggestions work on the backend was merged into the suggestions branch in this PR: https://github.com/goavki/apertium-apy/pull/18

Overall, the suggestions route works and is almost production ready, but the following needs to be taken care of (feel free to add anything in the comments):
- The UI in html tools needs refinement. @ftyers and @jonorthwash had some ideas, we could discuss this here.
- Tests could be written for apy endpoints.
- The whole mechanism could use a lot of rigorous testing, there might be bugs.
- ReCAPTCHA API supports localizations and I was thinking of integrating that during the GCI task, but it slipped out of my mind, could be a great idea.

Current interface is at https://github.com/svineet/apertium-html-tools/tree/suggest-word and some of that work was merged into https://github.com/goavki/apertium-html-tools/tree/suggestions but my later improvements still have open PRs to the suggestions branch of html-tools. So we need to work on organizing that stuff.