Update and move to reflect changes in programmes

As discussed with @anjumshabbir, this restructure of the service manager programme content:
* splits up a big page that was becoming unwieldy with the addition of a third programme
* changes terminology to "learning and development" to reflect users' vocabulary and broader scope of programme now
* moves to a new "learning and development" sub-folder within "the team". Previous user journey via "service manager" page was quite complex

I've reviewed this within Skills team and tested copy with four sample users whose feedback has led to some clarification of terms.

When deploying, please redirect the old page /service-manual/the-team/induction-and-development.html to the new folder /service-manual/the-team/learning-and-development