Remove dollar sign in command (#26)

Author: kianmeng

README.md

@@ -88,12 +88,19 @@ to run the fuzzing test suite. The `docker-compose.yml` sets up an Elixir
 container, a simple websocket echo server, and the Autobahn|Testsuite fuzzing
 server.
 
+In host:
+
+```sh
+docker-compose up -d
+docker-compose exec app bash
 ```
-(host)$ docker-compose up -d
-(host)$ docker-compose exec app bash
-(app)$ mix deps.get
-(app)$ mix test
-(app)$ iex -S mix
+
+In app:
+
+```sh
+mix deps.get
+mix test
+iex -S mix
 ```
 
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