Fix a few docs blocks

src/hb-glib.cc

diff --git a/src/hb-glib.cc b/src/hb-glib.cc
index 7dbd83d..e203524 100644
--- a/src/hb-glib.cc
+++ b/src/hb-glib.cc
@@ -383,6 +383,8 @@
 }
 
 /**
+ * hb_glib_blob_create:
+ *
  * Since: 0.9.38
  **/
 hb_blob_t *