* Update README.md and files in the doc folder to fit the new version
 of CI/CD config files
* Update variables in common file to fit the newly created Docker images
* Insert C31 board build and deploy jobs
* Remove files used in previous integration tests

* Insert Edgehog Docker image instead of that from container registry
* Perform only manifest integration

The yamllint job was included in the pipeline implicitly via the
inclusion of common.yml. This is not very transparent. Make the common
definition a base job and extend it explicitly in each pipeline now.

Add infrastructure stage comment header into both yaml files.

This is the first step for reducing code duplicates.

BCS 746-000807

* Move all build, deploy and test stubs to the manifest-build.yml
* Create a new job to generate and trigger the build jobs dynamically
* Add the base jinja2 file for the build jobs.
* Add initial docs for the manifest pipeline
* Remove unused files

BCS 746-000808

This makes merging a project MR possible even if the manifest has
received new commits since the MR pipeline build has run. The developer
is responsible for deciding whether it is safe to merge it without
having a build based on the latest manifest.

BCS 746-000794

Also set yocto deploy job to manual to test merge.