I just added a new page into the Discourse admin section to customize Embedding. You can now choose a category to post in that relates to the host you embedded the site on.
The new page also gives you a sample embed code for your site that is easily customized, and longer form descrptions of all the options. I’ve removed all embedding settings from the Settings tab to keep it all in one place. (the guides will have to be updated once we get this into stable.)