README.rst style fix

pos_keyboard/README.rst

@@ -5,16 +5,19 @@ Module to connect an additional usb keyboard for Point of Sale.
 ================================================================
 The processed keys:
 ----------------------------
-
-1. numChar: 0-9, '.'
-2. mode: 
-* qty: '/'[1]_ or "q"[2]_    
-* disc: '-'[1]_ or 'd'[2]_
-* price: '*'[1]_ or 'p'[2]_
-3. backspace: 'backspace'
-4. +/-: '+'[1]  or 's'[2]_
-
-[1]_ key on additional keyboard
-[2]_ key on basic keyboard
-
+=========== ===================== =================
+             additional keyboard   basic keyboard  
+=========== ===================== =================
+numChar      0-9                   0-9
+=========== ===================== =================
+mode qty     '/'                   'q'
+=========== ===================== =================
+mode disk    '-'                   'd'
+=========== ===================== =================
+mode price   '*'                   'p'
+=========== ===================== =================
+backspace    backspace             backspace
+=========== ===================== =================
+dot          '.'                   '.'
+=========== ===================== =================