Add a cheat sheet for configs and better folder structure for core modules

docs/source/modules/formatter.md

@@ -3,4 +3,10 @@
 Formatter modules are used to format the data extracted from a URL into a specific format. Currently the most widely-used formatter is the HTML formatter, which formats the data into an easily viewable HTML page.
 
 ```{include} autogen/formatter.md
+```
+
+```{toctree}
+:depth: 1
+:glob:
+autogen/formatter/*
 ```