Add support for Anki (output format)

[humenda]

Anki is a program to help memorising translations using flash cards. These could be auto-generated from FD dictionaries.
The project is at https://apps.ankiweb.net/

There are free and open versions both for desktop computers and Android.

[micha137]

Found format description. Apparently, .apkg files are zipped sqlite databases.

[karlb]

I've created anki decks by uploading a csv on their website. So some CSV->anki converter must already exist.

When creating the decks, I found a rough importance rating very valuable. Is there already some consensus on how to encode importance or usage frequency information in our dictionaries?

[karlb]

The two most promising ways to automate Anki to import and publish new decks seem to be

1. https://foosoft.net/projects/anki-connect/
2. https://github.com/patarapolw/ankisync

[karlb]

See https://github.com/freedict/tools/tree/master for the current state of an implementation using ankisync.

Todo:

• Decide which data should go into each flash card
• Choose sensible subset of entries for anki deck