Import the patch of Eckehard Berns to add insert mode. Thanks!

st.info

@@ -153,6 +153,7 @@ st| simpleterm,
 	ritm=\E[23m,
 	rmacs=\E(B,
 	rmcup=\E[?1049l,
+	rmir=\E[4l,
 	rmkx=\E[?1l\E>,
 	rmso=\E[23m,
 	rmul=\E[m,
@@ -168,6 +169,7 @@ st| simpleterm,
 	sitm=\E[3m,
 	smacs=\E(0,
 	smcup=\E[?1049h,
+	smir=\E[4h,
 	smkx=\E[?1h\E=,
 	smso=\E[3m,
 	smul=\E[4m,