Add README file.
Add README file.

Change-Id: I8a92b40a44d2208ece74bfe09d736a631b23ef43
Signed-off-by: Piotr Sikora <321b1a11e6b8c7ca12f1b0b438664e52a48b555e@frickle.com>

simpl/ngx_mongo,simpl/ngx_mongo,noname007/ngx_mongo,noname007/ngx_mongo