Add support for insert key

Insert key stands for a key which allows enter or leaves insert mode, so let
it generates the correct sequence to change between these modes:

   - Insert: Enter in insert mode.
   - Shift + Insert: Leave insert mode (replace mode).
   - Control + Insert: Insert a blank line.

Like Shift + Insert also paste text, if a user want this feature be full
functional he has to modify such shortcut.
---
 config.def.h |   16 ++++++++++++----
 st.info      |    3 +++
 2 files changed, 15 insertions(+), 4 deletions(-)

1 files changed, 3 insertions, 0 deletions

diff --git a/st.info b/st.info
index d0064db..4fc9bdb 100644
--- a/st.info
+++ b/st.info
@@ -138,6 +138,9 @@ st| simpleterm,
         kf62=\E[1;4Q,
         kf63=\E[1;4R,
         khome=\E[1~,
+        kil1=\E[2;5~,
+        krmir=\E[2;2~,
+        kich1=\E[2~,
         knp=\E[6~,
         kmous=\E[M,
         kpp=\E[5~,