Undocumented build instructions and dependency on container-structure-test for running 'make test'

[dbrugman-pega]

Describe the bug
The README.md doesn't include the (trivial) instructions on how to build the image ('make all'), nor how to execute the tests ('make test'). Further, to run the tests the Google Container Structure Tests tool needs to be installed (https://github.com/GoogleContainerTools/container-structure-test) - which has not been documented

To Reproduce
After building the image ('make all') execute the tests ('make test'). This will fail with the following message:

# Execute test cases
container-structure-test test --image qualitytest --config tests/pega-web-ready-testcases.yaml
make: container-structure-test: Command not found
make: *** [Makefile:14: test] Error 127

After installing the Container Sructure Test tool the tests will pass

Expected behavior
The build & test instructions should be documented, including the required dependency on Container Structure Test

Screenshots
n/a

Desktop (if applicable, please complete the following information):

• OS: Ubuntu 20.4.1
• Browser: n/a
• Version: n/a

Server (if applicable, please complete the following information):
n/a

Additional context
none

[kishorv10]

US-613495 (internal)