add missing <<EOF in the installation process

License MIT

installation.rst

@@ -15,7 +15,7 @@ Installation
     $ apt install apg
     $ PASSWORD=$(apg -n 1 -M NCL -m 20)
     $ apt install postgresql
-    $ su - postgres -c psql
+    $ su - postgres -c psql <<EOF
     CREATE ROLE authentic2 WITH LOGIN SUPERUSER PASSWORD '$PASSWORD';
     ALTER ROLE authentic2 SET client_encoding TO 'utf8';
     CREATE DATABASE authentic2;