adding asciiref gen hook

.githooks/pre-commit/01_asciiref_gen

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+origdir="${PWD}"
+docsdir="${PWD}/ref/ascii/"
+
+if ! command -v asciidoctor &> /dev/null;
+then
+        exit 0
+fi
+
+cd "${docsdir}"
+
+asciidoctor -o ascii.html ascii.adoc
+
+cd ${origdir}
+git add "${docsdir}/ascii.html"