[indic] Add github URL
diff --git a/src/hb-ot-shape-complex-indic.cc b/src/hb-ot-shape-complex-indic.cc
index 97cec38..0232b30 100644
--- a/src/hb-ot-shape-complex-indic.cc
+++ b/src/hb-ot-shape-complex-indic.cc
@@ -203,7 +203,8 @@
   else if (unlikely (hb_in_range (u, 0x17CDu, 0x17D1u) ||
 		     u == 0x17CBu || u == 0x17D3u || u == 0x17DDu)) /* Khmer Various signs */
   {
-    /* These can occur mid-syllable (eg. before matras), even though Unicode marks them as Syllable_Modifier. */
+    /* These can occur mid-syllable (eg. before matras), even though Unicode marks them as Syllable_Modifier.
+     * https://github.com/roozbehp/unicode-data/issues/5 */
     cat = OT_M;
     pos = POS_ABOVE_C;
   }