ide: make snippets for semantic UI

[erichanson]

There's so much cool stuff Semantic UI can do but there's a lot to it. Make snippets using the new snippet feature for dropping in templated examples of each Semantic UI component. I've been trying the convention of using __SCHEMA_NAME__ style snippets, to make them easy to notice and replace. It would actually be easy to prompt for a form that you fill out and it does the template replacement for you, asking for each variable on the page and then search and replacing it.