[website] fix `developing-binary-protocol` page
### Motiviation
old website has a customized template on formating protobuf file
into website. it is hard to achieve in the new website.
### Changes
Changes to a hyperlink to point back to the protobuf definition file at github.
@@ -549,9 +549,4 @@ message CommandPartitionedTopicMetadataResponse {
## Protobuf interface
-{% include protobuf.html %}
-
-
-
-
-
+All Pulsar's Protobuf definitions can be found {@inject: github:here:/pulsar-common/src/main/proto/PulsarApi.proto}.
