navi: Add freqtrade cheat sheet

navi/misc.cheat

@@ -1,5 +1,11 @@
 % misc
 
+# Update system
+sudo apt update && sudo apt upgrade
+
+# Clean APT
+sudo apt autoclean && sudo apt autoremove
+
 # List users
 cat /etc/passwd | awk -F: '{ print $1}'