Update README.md

Author: j2doll

README.md

@@ -8,6 +8,8 @@
 
 ## Example
 
+### :one: number to string
+
 ```cpp
     std::cout << " [1] ------------ " << std::endl ;
 
@@ -16,15 +18,45 @@
     std::cout << "   2 : " << QXlsx::columnNumberToString( 2 ) << std::endl ;
     std::cout << " 100 : " << QXlsx::columnNumberToString( 100 ) << std::endl ;
     std::cout << " UINT_MAX : " << QXlsx::columnNumberToString( UINT_MAX ) << std::endl ;
-	
+```
+
+- Output : 
+
+```
+ [1] ------------ 
+   0 : 
+   1 : A
+   2 : B
+ 100 : CV
+ UINT_MAX : MWLQKWU
+```
+
+### :two: alphabet to number
+
+```cpp
     std::cout << " [2] ------------ " << std::endl ;
 
     std::cout << " a : " << QXlsx::alphabetToNumber('a') << std::endl ;
     std::cout << " z : " << QXlsx::alphabetToNumber('z') << std::endl ;
     std::cout << " A : " << QXlsx::alphabetToNumber('A') << std::endl ;
     std::cout << " Z : " << QXlsx::alphabetToNumber('Z') << std::endl ;
     std::cout << " 5 : " << QXlsx::alphabetToNumber('5') << std::endl ;
+```
+
+- Output : 
 
+```
+ [2] ------------ 
+ a : 1
+ z : 26
+ A : 1
+ Z : 26
+ 5 : 0
+``` 
+
+### :three: string to number
+
+```cpp
     std::cout << " [3] ------------ " << std::endl ;
 
     std::string columnString = "AB";
@@ -37,18 +69,6 @@
 - Output : 
 
 ```
- [1] ------------ 
-   0 : 
-   1 : A
-   2 : B
- 100 : CV
- UINT_MAX : MWLQKWU
- [2] ------------ 
- a : 1
- z : 26
- A : 1
- Z : 26
- 5 : 0
  [3] ------------ 
 28   AB
 ```