Combine template library repositories

[jrha]

Merge template-library-core and template-library-standard into a single repository named template-library, the history must be preserved https://github.com/unravelin/tomono may help with this.

Hold off on merging template-library-os and template-library-grid until we can reach a consensus on what to do with the multiple "master" branches.

[jrha]

• Documentation will also need to be updated to reflect new locations.
• Release and build_all_repos scripts will need to ne updated to operate on new locations.

[ned21]

Agreed at RAL workshop that it would be nice to consolidate all templates into one repository but first need agreement on whether we can move away from the per-release development workflow which would cause a single repo to have an unmaintainable number of branches.

[jrha]

Individual repository indentity should translate to subdirectories, e.g.
Files from template-library-core should go in to a subdirectory named core.

[jrha]

Not likely to happen without actual time put aside to do it, which I can't promise right now.