added doc comments to all formatters

html_to_django/formatters/for_formatter.py

@@ -1,3 +1,16 @@
+"""
+for_formatter.py
+
+This module contains a function `format` that modifies a BeautifulSoup object in place.
+The function searches for all elements with the attribute "dj-for". The value of "dj-for" is expected to be a
+string representing a Django template for loop. For each found element, it inserts a Django template for loop
+before the element and an endfor tag after the element, using the value of "dj-for" as the loop. Then it removes
+the element's original tag, leaving only the Django template for loop.
+
+Example:
+    If an element is <div dj-for="item in list"></div>,
+    after processing, it becomes {% for item in list %}{% endfor %}.
+"""
 from bs4 import BeautifulSoup