fix style README.rst

pos_keyboard/README.rst

@@ -5,21 +5,16 @@ Module to connect an additional usb keyboard for Point of Sale.
 ================================================================
 The processed keys:
 ----------------------------
-number: 0-9
-............................
-mode: 
-............................
- qty: '/'* or "q"**
- disc: '-'* or 'd'**
- price: '*'* or 'p'**
-............................
-dot: '.'
-............................
-backspace: 'backspace'
-............................
-+/-: '+'*  or 's'**
-............................
-* key on additional keyboard
-** key on basic keyboard
-============================
+
+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
+