Update bash_head.html

Author: qwelias

src/bash_head.html

@@ -1,3 +1,4 @@
+<pre>
 #!/usr/bin/env bash
 set -o errexit
 set -o errtrace
@@ -6,3 +7,4 @@
 shopt -s globstar
 shopt -s nullglob
 # set -o xtrace
+</pre>