No doc for how to add this shard into shard.yml.

[zw963]

Just for mention, as followed by most of crystal shard, we should add a entry for told user how to use it (~let user copy~) when user want to try this shard.

Thanks

[ralsina]

Good catch! Done in c95658320c6f9a491bb4e43717cca6acaedf6cb