Rename from branchingPolicy.png to BranchingPolicy.png to fit with the reference in the Readme.md file

# Conflicts:
#	README.md

Main readme and Visual Studio code enhancement

See merge request !2

Moved API and UseCases at top level.

Use case model master document and associated drawio diagram
PlantUML diagrams
	Sequence diagram of the SetupTrackable use case
	Sequence diagrams of the underlying API calls