Update README.md

Author: josemoracard

exercises/006.1-square_value_of_number/README.md

@@ -1,21 +1,21 @@
 # `006.1` square value of number
 
-## 📝 Instructions
+## 📝 Instructions:
 
 1. Write a function called `square()` that calculates the square value of a number.
 
-## Example input:
+## 📎 Example input:
 
 ```py
 square(6)
 ```
 
-## Example output:
+## 📎 Example output:
 
 ```py
 36
 ```
 
 ## 💡 Hint:
 
-+ Using the `**` operator
++ Using the `**` operator.