[Docs] adding params - fix gRPC status error code

[bryanchriswhite]

Summary

func (k msgServer) UpdateParam(ctx context.Context, msg *examplemodtypes.MsgUpdateParam) (*examplemodtypes.MsgUpdateParamResponse, error) {
	// ...
	if k.GetAuthority() != msg.Authority {
		return nil, status.Error(
-			codes.InvalidArgument,
+			codes.PermissionDenied,
			examplemodtypes.ErrExamplemodInvalidSigner.Wrapf(
				"invalid authority; expected %s, got %s",
				k.GetAuthority(), msg.Authority,
			).Error(),
		)
	}
	// ...
}

Issue

• N/A

Type of change

Select one or more from the following:

• New feature, functionality or library
• Consensus breaking; add the consensus-breaking label if so. See [Infra] Automatically add the consensus-breaking label #791 for details
• Bug fix
• Code health or cleanup
• Documentation
• Other (specify)

Testing

• Documentation: make docusaurus_start; only needed if you make doc changes
• Unit Tests: make go_develop_and_test
• LocalNet E2E Tests: make test_e2e
• DevNet E2E Tests: Add the devnet-test-e2e label to the PR.

Sanity Checklist

• I have tested my changes using the available tooling
• I have commented my code
• I have performed a self-review of my own code; both comments & source code
• I create and reference any new tickets, if applicable
• I have left TODOs throughout the codebase, if applicable