ci: Update pages deployment
* Fix name of script
* Add rule to run on MR
* Copy the output files to artefact
Signed-off-by: 
Chris Swinchatt <christopher.swinchatt@arm.com>
* Fix name of script
* Add rule to run on MR
* Copy the output files to artefact
Signed-off-by: Chris Swinchatt <christopher.swinchatt@arm.com>