mention zstd binary in the readme

Readme.md

@@ -24,6 +24,7 @@ Measuring with the 'time' utility the original zstd and my decoder both decoding
 1. Decode all of them correctly into the output buffer
 1. Decode all the decode_corpus files (1000+) I created locally
 1. Calculate checksums
+1. Act as a `zstd -c -d` dropin replacement
 
 ## Cannot do
 
@@ -61,6 +62,8 @@ This will tell you where the decoder panics exactly. If you are able to fix the
 
 # How can you use it?
 
+Additionally to the descriptions and the docs you can have a look at the zstd / zstd_streaming binaries. They showcase how this library can be used.
+
 ## Easy
 
 The easiest is to wrap the io::Read into a StreamingDecoder which itself implements io::Read. It will decode blocks as necessary to fulfill the read requests