Add scrollback mouse patch

.gitignore

@@ -22,4 +22,4 @@
 !/st-dracula-0.8.2.diff
 !/st-hidecursor-0.8.3.diff
 !/st-scrollback-20200419-72e3f6c.diff
-!/st-universcroll-0.8.4.diff
+!/st-scrollback-mouse-20191024-a2c479c.diff

config.def.h

@@ -181,6 +181,8 @@ static uint forcemousemod = ShiftMask;
  */
 static MouseShortcut mshortcuts[] = {
 	/* mask                 button   function        argument       release */
+	{ ShiftMask,            Button4, kscrollup,      {.i = 1} },
+	{ ShiftMask,            Button5, kscrolldown,    {.i = 1} },
 	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},      1 },
 	{ ShiftMask,            Button4, ttysend,        {.s = "\033[5;2~"} },
 	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },

st-scrollback-mouse-20191024-a2c479c.diff

@@ -0,0 +1,13 @@
+diff --git a/config.def.h b/config.def.h
+index ec1b576..4b3bf15 100644
+--- a/config.def.h
++++ b/config.def.h
+@@ -163,6 +163,8 @@ static uint forcemousemod = ShiftMask;
+  */
+ static MouseShortcut mshortcuts[] = {
+ 	/* mask                 button   function        argument       release */
++	{ ShiftMask,            Button4, kscrollup,      {.i = 1} },
++	{ ShiftMask,            Button5, kscrolldown,    {.i = 1} },
+ 	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},      1 },
+ 	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },
+ 	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\005"} },