added readme to lib
added readme to lib

Signed-off-by: Mark Johnston <ec775f859c89f21868d2baeb872574d39a5c14ad@gmail.com>

unicefuganda/edtrac,dimagi/rapidsms-core-dev,caktus/rapidsms,eHealthAfrica/rapidsms,ehealthafrica-ci/rapidsms,ken-muturi/rapidsms,dimagi/rapidsms-core-dev,catalpainternational/rapidsms,ken-muturi/rapidsms,ken-muturi/rapidsms,lsgunth/rapidsms,caktus/rapidsms,lsgunth/rapidsms,unicefuganda/edtrac,caktus/rapidsms,peterayeni/rapidsms,catalpainternational/rapidsms,ehealthafrica-ci/rapidsms,peterayeni/rapidsms,lsgunth/rapidsms,dimagi/rapidsms,rapidsms/rapidsms-core-dev,lsgunth/rapidsms,ehealthafrica-ci/rapidsms,catalpainternational/rapidsms,dimagi/rapidsms,eHealthAfrica/rapidsms,peterayeni/rapidsms,catalpainternational/rapidsms,rapidsms/rapidsms-core-dev,peterayeni/rapidsms,unicefuganda/edtrac,eHealthAfrica/rapidsms