This PR changes/adds the following behavior,

1. Use a custom template to allow namespace access from within the workspace.
2. Create and mount a pr namespace scoped kubeconfig to the coder pod and workspace pod. (you can update the deployment from within the workspace)
3. Remove the --skip-build flag from ./scripts/deploy-pr.sh and add the --build and --deploy flags to force a new build or deploy.
4. Update related documentation.