Clarify complex filters param usage, pre-release compat (#285)

Clarify complex filters parameter usage, pre-release compat

Author: rpkilby

README.rst

@@ -32,6 +32,11 @@ Using ``django-rest-framework-filters``, we can easily do stuff like::
 
 ----
 
+**!** The 1.0 pre-release is compatible with django-filter 2.x and can be installed with
+``pip install --pre``.
+
+----
+
 .. contents::
     **Table of Contents**
     :local:
@@ -534,7 +539,10 @@ Below is the procedure for encoding a complex query:
 * URL-encode the individual querystrings.
 * Wrap the encoded strings in parentheses, and join with operators.
 * URL-encode the entire querystring.
-* Set as the value to the complex filter param (default: ``filters``).
+* Set as the value to the complex filter param (e.g., ``?filters=<complex querystring>``).
+
+Note that ``filters`` is the default parameter name and can be overridden in the backend class.
+
 
 Using the first example, these steps can be visualized as so: