drop echoist example in docs

docs/examples/echoist.md

-# Echoist
-
-This is a simple demo service. It accepts TCP connections and echoes what they sent.
-
-## What it does?
-
-1. Binds port 7
-2. Drops privileges via fork - switches to _daemon_ user and group
-3. Runs until SIGTERM/SIGKILL is received

docs/index.rst

@@ -12,7 +12,6 @@ Welcome to satella's documentation!
        instrumentation/traceback
        instrumentation/metrics
        source/modules
-       examples/echoist
        posix