Python: Add change note for new taint-tracking configuration API. Needs links to full documentation added.

Author: markshannon

change-notes/1.20/analysis-python.md

@@ -11,6 +11,7 @@ Removes false positives seen when using Python 3.6, but not when using earlier v
 The API has been improved to declutter the global namespace and improve discoverability and readability.
  * New predicates `ModuleObject::named(name)` and `ModuleObject.attr(name)` have been added, allowing more readable access to common objects. For example, `(any ModuleObject m | m.getName() = "sys").getAttribute("exit")` can be replaced with `ModuleObject::named("sys").attr("exit")`
  * The API for accessing builtin functions has been improved. Predicates of the form `theXXXFunction()`, such as `theLenFunction()`, have been deprecated in favour of `Object::builtin(name)`.
+ * A configuration based API has been added for writing data flow and taint tracking queries. This is provided as a convenience for query authors who have written data flow or taint tracking queries for other languages, so they can use a similar format of query across multiple languages.
 
  ## New queries