Update the document of likecoin-button

[piechai]

In the current user guide of the likecoin-button (user-guide/creator/likecoin-button.md), it described three actions: clap hand to like and superlike the page, save the page and follow. However, the current implementation of the likecoin-button has 4 actions: clap hand, save the page, support the author and register as a liker. I propose to align the document with current implementation to better present the current feature to the user.