Update release instructions

The "Demo" section doesn't exist any more.

README.rst

@@ -171,7 +171,7 @@ Development
 
 Releasing a new Version
 -----------------------
-1. Consider updating ``screenshot.png`` and `the Demo section`_, push those changes.
+1. Consider updating `the Output section`_, push those changes.
 2. Do ``git tag`` and think about what the next version number should be.
 3. Do ``git tag --annotate 1.2.3`` to set the next version number. The
    text you write for this tag will show up as the release description on Github,
@@ -270,7 +270,7 @@ DONE
 * Print ``$SUDO_USER`` value with process details, if set
 * Run CI on both Python 2 and Python 3
 
-.. _the Demo section: #demo
+.. _the Output section: #output
 .. _download the latest px.pex: https://github.com/walles/px/releases/latest
 .. _Unix domain sockets: https://en.wikipedia.org/wiki/Unix_domain_socket
 .. _Releases: https://github.com/walles/px/releases