updating Changelog for release 2.0

Changelog.md

@@ -22,3 +22,24 @@ This changelog covers the entire dave project which includes a few repositories,
   - [Evaluation of current DVL plugins ](https://github.com/Field-Robotics-Lab/dave/wiki/dvl_description)
   - [Evaluation of current forward-looking/multibeam sonar plugins](https://github.com/Field-Robotics-Lab/dave/wiki/dvl_description)
 
+## [2.0.0] - 2020-09-25
+
+### Added
+
+- Visual models of
+  - New vehicles (Smilodon, Caracara and Caldus): [dave PR #54](https://github.com/Field-Robotics-Lab/dave/pull/54), [#62](https://github.com/Field-Robotics-Lab/dave/pull/62) and [#67](https://github.com/Field-Robotics-Lab/dave/pull/67) 
+  - Three Glider Models: [dave PR #31](https://github.com/Field-Robotics-Lab/dave/pull/31)
+  - Predator Manipulator: [dave PR #26](https://github.com/Field-Robotics-Lab/dave/pull/26)
+- Sensor Functionality
+  - USBL dev [dave PR #50](https://github.com/Field-Robotics-Lab/dave/pull/50) and [#60](https://github.com/Field-Robotics-Lab/dave/pull/60) 
+  - Prototype of Depth camera sonar [nps_uw_sensors_gazebo PR #13](https://github.com/Field-Robotics-Lab/nps_uw_sensors_gazebo/pull/13)
+  - DVL upgrade to include current profiling [nps_uw_sensors_gazebo PR #15](https://github.com/Field-Robotics-Lab/nps_uw_sensors_gazebo/pull/15)
+  - Improved underwater lidar model, standalone and mounted to vehicle [dave PR #66](https://github.com/Field-Robotics-Lab/dave/pull/66) and [nps_uw_sensors_gazebo PR #17](https://github.com/Field-Robotics-Lab/nps_uw_sensors_gazebo/pull/17) 
+- Environmental Plugins
+  - Bathymetry: generate DEM models directly from mapping data [dave PR 44](https://github.com/Field-Robotics-Lab/dave/pull/44).
+  - Occluded objects on seafloor [dave PR 43](https://github.com/Field-Robotics-Lab/dave/pull/43)
+- Manipulation: Electrical mating plugin enhancement [dave PR #40](https://github.com/Field-Robotics-Lab/dave/pull/40)
+- Documentation, descriptions and tutorials
+  - Additional demonstrations and tutorials described on [dave wiki page](https://github.com/Field-Robotics-Lab/dave/wiki)
+  - [Evaluation of Ocean Current Plugin Capabilities](https://github.com/Field-Robotics-Lab/dave/wiki/Ocean-Current)
+- Github Action for Continuous Integration [dave PR #39](https://github.com/Field-Robotics-Lab/dave/pull/39) and [nps_uw_sensors_gazebo PR 16](https://github.com/Field-Robotics-Lab/nps_uw_sensors_gazebo/pull/16)