Submodule URLs are weird

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "protos/api_upstream"]
 	path = protos/api_upstream
-	url = git@github.com:temporalio/api.git
+	url = git://github.com:temporalio/api.git

README.md

@@ -1 +1,9 @@
 Core SDK that can be used as a base for all other SDKs.
+
+# Getting started
+This repo uses a submodule for upstream protobuf files. The path `protos/api_upstream` is a 
+submodule -- when checking out the repo for the first time make sure you've run 
+`git submodule update --init --recursive`. TODO: Makefile.
+
+## Dependencies
+* Protobuf compiler

protos/core_interface.proto

@@ -3,7 +3,8 @@ syntax = "proto3";
 package temporal.api.coresdk.v1;
 
 // Note: Intellij will think these imports don't work because of the slightly odd nature of
-// the include paths. They work.
+// the include paths. You can make it work by going to the "Protobuf Support" settings section
+// and adding the "api_upstream" subdir as an include path.
 
 import "temporal/api/workflowservice/v1/request_response.proto";
 import "temporal/api/taskqueue/v1/message.proto";