patch 8.0.0764: 'termkey' does not work yet

Problem:    'termkey' does not work yet.
Solution:   Implement 'termkey'.
diff --git a/src/version.c b/src/version.c
index e2ab84c..ed58049 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    764,
+/**/
     763,
 /**/
     762,