Google Code-in

We're currently running this slack invite plugin:

https://github.com/Epiphic/dokuwiki-slack-invite

We'd like some changes: 1) Extend to user ReCATPCHA v3 (but still support v2, i.e. add a new variable there) 2) Our website runs behind cloudflare. This means that our server doesn't get the IP address from the user directly but cloudflare's IP address, which is less useful. Extend the plugin to support getting the actual user IP address IF cloudflare is being used. This is actually easy:

https://stackoverflow.com/questions/14985518/cloudflare-and-logging-visitor-ip-addresses-via-in-php

3) The form do some character validation and if you enter invalid characters it issues an error. However some characters should be allowed, for example spaces. After all, many people have two words in their names or last names.