(add) Annotation store initial API design
(add) Annotation store initial API design

       Reasons
=====================
1. The API needs to be designed in order to be commnunicated.
2. The creation and retrieval of annotations has to be contained in the
backend application for mobility. This is why API has to be a function
of the backend service.

       Changes
=====================
1. Added GET and POST methods for getting and creating the annotations
on a listory.

SWE574-Nerds/friendly-eureka,SWE574-Nerds/friendly-eureka,SWE574-Nerds/friendly-eureka,SWE574-Nerds/friendly-eureka