add nanopb (manual)

components/spotify/cspot/bell/nanopb/tests/comments/comments.proto

@@ -0,0 +1,17 @@
+syntax = "proto2";
+
+// Message1Comment
+message Message1
+{
+    // LeadingMemberComment
+    required int32 member1 = 1;
+    required int32 member2 = 2; // TrailingMemberComment
+}
+
+// Enum1Comment
+enum Enum1
+{
+    // LeadingEnumComment
+    ENUMVAL1 = 1;
+    ENUMVAL2 = 2; // TrailingEnumComment
+}