ssh: add info about escape sequences

Most useful for terminating unresponsive sessions

sheets/ssh

@@ -51,3 +51,8 @@ sshfs name@server:/path/to/folder /path/to/mount/point
 # Emacs can read file through SSH
 # Doc: http://www.gnu.org/software/emacs/manual/html_node/emacs/Remote-Files.html
 emacs /ssh:name@server:/path/to/file
+
+# Get help on SSH escape sequences
+# Useful for terminating unresponsive sessions
+# The default escape character is ~ (tilde), escapes are only recognized immediately after newline
+$ [Enter]~?