edit readme

Author: handiko

README.md

@@ -5,7 +5,7 @@
 ## Index
 1. [HDLC Packet Encoder](./hierblocks/hdlc-packet-encoder/README.md)
 2. [AFSK Modulator](./hierblocks/afsk-modulator/README.md)
+3. [AFSK Bell 202 Modulator](./hierblocks/afsk-bell202-modulator/README.md)
 
 ## TODO
-
-// *TODO*
+* Bundle it up into one installable module using gr-modtool