Provide Documentation to Set Up Shared `-contrib` and `sdk` Workspace

What problem do you want to solve?

I've recently investigated #3895 which potentially spans both the opentelemetry-python-contrib and the opentelemetry-python repositories. Both of these repositories have great configuration to set up uv workspaces for everything that is contained within the respective repository, but there is no documentation on how to setup a shared environment for both repositories to troubleshoot or develop across the boundary between the contrib and non-contrib repo.

Describe the solution you'd like

I'd like to add documentation and potentially configuration to this repository on how to setup local workspaces that include local versions of both opentelemetry-python-contrib and opentelemetry-python, instead of having separate workspaces that, in case of the opentelemetry-python-contrib repo, always install opentelemetry-python as a packaged dependency instead of utilizing a locally cloned version.

Describe alternatives you've considered

No response

Additional Context

No response

Would you like to implement a fix?

Yes

Tip

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Start by reading the existing uv workspace configuration in opentelemetry-python-contrib and opentelemetry-python, then compare how each repository handles its local dependencies. Document or configure a shared workspace that uses local checkouts of both repositories; it is done when contributors can follow the instructions to develop and troubleshoot across the repository boundary.