Adjusted documentation with new exception names

Author: sergioteula

docs/index.rst

@@ -29,9 +29,10 @@ Usage guide
 Migration guide
 ---------------
 
-If you are still using version 3.x or lower, it is highly recommended upgrading to the latest version.
+If you are still using version 4.x or lower, it is highly recommended upgrading to the latest version.
 
 .. toctree::
     :maxdepth: 1
 
-    ./pages/migration-guide.md
+    ./pages/migration-guide-4.md
+    ./pages/migration-guide-5.md

docs/pages/migration-guide.md docs/pages/migration-guide-4.mddocs/pages/migration-guide.md renamed to docs/pages/migration-guide-4.md

@@ -1,4 +1,4 @@
-# Migration guide
+# Migration guide from 3.x to 4.x
 
 This guide explains how to proceed with the migration from version 3.x to version 4.x of your current code.
 If you are still using the old version, it is highly recommended to update, since you wont get any future

docs/pages/migration-guide-5.md

@@ -0,0 +1,40 @@
+# Migration guide from 4.x to 5.x
+
+This guide explains how to proceed with the migration from version 4.x to version 5.x of your current code.
+If you are still using the old version, it is highly recommended to update, since you wont get any future
+updates nor new features.
+
+## Changelog summary
+
+- Updated custom exceptions names.
+
+## How to upgrade?
+
+Upgrading to the last version of this module is as easy as running this pip command:
+
+    pip install python-amazon-paapi --upgrade
+
+## What should I change in my current code?
+
+### Exceptions
+
+Exceptions names have changed, removing the `Exception` part of the name or replacing it
+with `Error`. They should be adjusted as bellow:
+
+```python
+AmazonException                 ->  AmazonError
+AsinNotFoundException           ->  AsinNotFound
+AssociateValidationException    ->  AssociateValidationError
+InvalidArgumentException        ->  InvalidArgument
+InvalidPartnerTagException      ->  InvalidPartnerTag
+ItemsNotFoundException          ->  ItemsNotFound
+MalformedRequestException       ->  MalformedRequest
+ApiRequestException             ->  RequestError
+TooManyRequestsException        ->  TooManyRequests
+```
+
+### I need more help
+
+You can always ask for help in our [Telegram group](https://t.me/PythonAmazonPAAPI) or raise an issue on
+[Github](https://github.com/sergioteula/python-amazon-paapi/issues) for help. If you find that this
+guide could be improved somehow, feel free to send a pull request with your changes.