Add twitter card meta data [WIP]

[item4]

I want to introduce cottage in twitter. But this website did not have metadata for twitter. I suggest insert more info.

Known problems

1. I don't know your twitter account. I can not fill twitter:creator field. Please tell me your twitter account.
2. I want to know your intention about twitter account for cottage project. If you want it, please make it and tell me account name.

[therne]

I don't have any twitter account 😢 i will make it soon!