Functions to interact with windows registry

I'm wondering if there'd be any appetite for template functions to read from the windows registry.

It'd be handy in my world to also expose other windows functions, such as service definitions or scheduled tasks, but the registry would be a useful start.

No files, tests, or entry points are named. Start by surveying the existing template-function implementation and any platform-specific integration, then determine the intended registry API and supported Windows behavior. Done would mean an agreed scope for registry access, with implementation and tests covering that scope.

Written by the indexing model from the issue text.