add a readme file for pyheron (#1944)

* add a readme file for pyheron

* added the URL for streamparse
diff --git a/scripts/packages/BUILD b/scripts/packages/BUILD
index a8ce011..743bbad 100644
--- a/scripts/packages/BUILD
+++ b/scripts/packages/BUILD
@@ -322,6 +322,7 @@
     srcs = [
         "pyheron/requirements.txt", 
         "pyheron/setup.py.template",
+        "pyheron/README.txt",
     ] + generated_release_files,
     outs = generated_pyheron_egg_file,
     stamp = 1,
diff --git a/scripts/packages/pyheron/README.txt b/scripts/packages/pyheron/README.txt
new file mode 100644
index 0000000..3fb0913
--- /dev/null
+++ b/scripts/packages/pyheron/README.txt
@@ -0,0 +1,3 @@
+PyHeron is the python API for Heron, the distributed streaming engine.
+The API is based on the streamparse Storm python API from Parsely. More
+details can be found at https://github.com/Parsely/streamparse