Move descriptions of avalanche problem kinds to a separate glossary page, or condense them somehow

[kellpossible]

They add a lot of extra words, which makes the forecast page longer, and perhaps more difficult to read, especially for experienced users who already understand the meaning of the technical terms.

We could move the description of these terms to a separate glossary page, or we could also have some kind of popup (not great on the phone), or collapsible section in order to hide the text by default.