docs: Improve the preview script

Author: eliandoran

bin/docs/preview.sh

@@ -1,5 +1,8 @@
 #!/usr/bin/env bash
 
+LISTEN_ADDRESS=127.0.0.1:8088
+
 script_dir=$(realpath $(dirname $0))
-output_dir="$script_dir/../docs"
-httpd -fv -p 127.0.0.1:8089 -h "$output_dir"
+output_dir="$script_dir/../../docs"
+echo "Preview the documentation at http://$LISTEN_ADDRESS"
+httpd -fv -p "$LISTEN_ADDRESS" -h "$output_dir"