doc: Drop documentation for ci.yml kas configuration file

The ci.yml kas configuration file relates to configuring EWAOL builds as part of
a continuous integration testing pipeline. As this is not relevant to readers of
the documentation, it is removed for simplicity.

Issue-Id: SCM-3893
Signed-off-by: Richard Neill <richard.neill@arm.com>
Change-Id: I94d9e41d95ae0326bc33026631852ba1063ca1a5