docs: add changelog for instruction set message

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Added
 
+- Add definition of instruction_set message
 - Added optional primitives to squad schema
 
 ### Changed
@@ -16,10 +17,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Refactor action schema to accept geojson.Points
 - Use geojson Point for platform_status
 - Add waypoint to platform_status
+- Updated header version to accept semver, branch or commit
 - Store remote schemas as committed local files
   This prevents the live runtime loading untested changes
-- Updated header version to accept semver, branch or commit
-- Store remote schemas as committed local files 
 - Refactored planning_configuration message definition
   - Remove region_of_interest and exclusion_zones
   - Add primitives array of classified geojson Features