[ADD] signals handler *

also reorganize the code

dev/signals.txt

@@ -0,0 +1,11 @@
+interactive:
+						EMPTY		FULL		HEREDOC:EM	HEREDOC:FU
+- ^C: nouveau prompt	new p		new p		new heredoc	new heredoc
+- ^D: exit				exit		-			empty line	-
+- ^\: nothing			-			-			-			-
+
+bash:
+						EMPTY		FULL		HEREDOC:EM	HEREDOC:FU
+- ^C: nouveau prompt	new p		new p		new p		new p
+- ^D: exit				exit		-			error		-
+- ^\: nothing			-			-			-			-

dev/supp

@@ -0,0 +1,6 @@
+{
+	ignore_readline_leaks
+	Memcheck:Leak
+	...
+	obj:*readline*
+}

dev/valgrind.sh

@@ -0,0 +1,2 @@
+#!/bin/bash
+valgrind --leak-check=full --show-leak-kinds=all --suppressions=dev/supp ./minishell