README.md correction

Author: majid shahbaz

README.md

@@ -52,7 +52,7 @@
  2.4.5. Convert `str` to `float` 
  2.4.6. Convert `int` to `float`
 
-### 3.Operators
+### 3. Operators
 #### 3.1. Assignment Operators
   3.1.1. = Equal to
   3.1.2. += Add and Assign