fix(guide): simplify directory structure

guide/english/python/learn-about-python-sets/index.md

@@ -0,0 +1,32 @@
+---
+title: Learn About Python Sets
+---
+`Set`s in Python are a type of mutable but unordered data structure, which can only contain *unique* elements. 
+
+**Creation:**
+
+`set` literal:
+
+Curly brackets, `{}`, *cannot* be used to create an empty set:
+
+```python
+>>> not_set = {}     # set constructor must be used to make empty sets.
+>>> type(not_set)    # Empty curly brackets create empty dictionaries.
+<class 'dict'>
+```
+
+You can only create an empty set by using the `set()` method.
+
+```python
+>>> example_set = set()
+>>> type(example_set)
+<class 'set'>
+```
+
+However, if elements are included within the curly brackets, then it would be acceptable syntax to create a set.
+
+```python
+>>> example_set_2 = {1, 2, 3}
+>>> type(example_set_2)
+<class 'set'>
+````