Add support for Supr key

Del : Delete character under cursor.
    Shift + Del : Delete the line under cursor.
    Ctrl + Del: Delete the full screen.
---
 config.def.h |   16 ++++++++++++----
 st.info      |    2 ++
 2 files changed, 14 insertions(+), 4 deletions(-)

st.info

@@ -71,6 +71,8 @@ st| simpleterm,
 	kRIT=\E[1;2C,
 	kind=\E[1;2B,
 	kri=\E[1;2A,
+	kclr=\E[3;5~,
+	kdl1=\E[3;2~,
 	kdch1=\E[3~,
 	kich1=\E[2~,
 	kend=\E[4~,