Add summary to chamber of secrets

- I'm getting really tired of answering "what is chamber of secrets" every other day in the G+ community. I
know that there will still be a few dozen users that will still ask what it is BUT at least now I can tell them
to fuck off and read the summary haha Anyways, if one of two read it then this will have served it's purpose

Change-Id: Ief0106adde980c96aba926f6d7eb01a2991c6717