Fix underscore display issue

Author: Qfc9

Python/README.md

@@ -129,7 +129,7 @@
   * tuple()
   * type()
   * zip()
-  * __main__()
+  * \_\_main__()
 
 5. Classes
  * class
@@ -140,10 +140,10 @@
  * Methods
  * Self
  * Instance Object
- * __init__(self)
- * __str__(self)
- * __iter__(self)
- * __next__(self)
+ * \_\_init__(self)
+ * \_\_str__(self)
+ * \_\_iter__(self)
+ * \_\_next__(self)
 
 
 6. Tasks