docs: Expand webhook documentation with comprehensive developer guide

libs/gl-client-py/glclient/__init__.py

@@ -448,6 +448,14 @@ def stream_log(self):
                 break
             yield nodepb.LogEntry.FromString(bytes(n))
 
+    def stream_incoming(self):
+        stream = self.inner.stream_incoming(b"")
+        while True:
+            n = stream.next()
+            if n is None:
+                break
+            yield nodepb.IncomingPayment.FromString(bytes(n))
+
     def stream_custommsg(self):
         stream = self.inner.stream_custommsg(b"")
         while True:

libs/gl-client-py/glclient/greenlight.proto

@@ -25,6 +25,7 @@ service Node {
 	//
 	// Currently includes off-chain payments received matching an
 	// invoice or spontaneus paymens through keysend.
+	rpc StreamIncoming(StreamIncomingFilter) returns (stream IncomingPayment) {}
 
 	// Stream the logs as they are produced by the node
 	//
@@ -120,6 +121,9 @@ message Amount {
 	}
 }
 
+// Options to stream_incoming to specify what to stream.
+message StreamIncomingFilter {
+}
 
 message TlvField {
 	uint64 type = 1;