Update docs to mention the proto3 API differences.
Fixes #15.
diff --git a/proto/lib.go b/proto/lib.go
index dcabe3b..6837512 100644
--- a/proto/lib.go
+++ b/proto/lib.go
@@ -70,6 +70,12 @@
with distinguished wrapper types for each possible field value.
- Marshal and Unmarshal are functions to encode and decode the wire format.
+When the .proto file specifies `syntax="proto3"`, there are some differences:
+
+ - Non-repeated fields of non-message type are values instead of pointers.
+ - Getters are only generated for message and oneof fields.
+ - Enum types do not get an Enum method.
+
The simplest way to describe this is to see an example.
Given file test.proto, containing