[IMP] document_page: Use html_diff for checking differences

document_page/readme/CONTRIBUTORS.md

@@ -8,8 +8,11 @@
   - Ernesto Tejeda
   - Víctor Martínez
 
-Trobz
+- Trobz
+  - Dung Tran \<<dungtd@trobz.com>\>
 
-- Dung Tran \<<dungtd@trobz.com>\>
 - [Sygel](https://www.sygel.es):
   - Ángel García de la Chica Herrera
+
+- [Dixmit](https://www.dixmit.com):
+  - Enric Tobella

document_page/readme/USAGE.md

@@ -5,3 +5,8 @@ To use this module, you need to:
   the template
 - Click on Pages to create pages and select the previous category to use
   the template
+
+## Improve diff of history
+
+If you want to improve how history is shown, you can install html_diff python library.
+A new comparison method will be installed.