refactor: add code structs

Author: kankenny

TODO.txt

@@ -44,7 +44,7 @@ Assign Labels to Data
 1.  Manually
 2.  Label Spreading
 3.  Active Learning
-4.  Online Learning
+    a.  Online Learning
 
 ###########################################
 

label_your_data/data_ops/label/label.py

@@ -0,0 +1,13 @@
+def assign_label():
+    raise NotImplementedError
+
+
+def label_spread():
+    raise NotImplementedError
+
+
+def active_learning():
+    def online_learning():
+        raise NotImplementedError
+
+    raise NotImplementedError