Remove dead links to API v1 docs

docs/advanced_topics/api/v2/usage.rst

@@ -2,11 +2,6 @@
 Wagtail API v2 Usage Guide
 ==========================
 
-.. note::
-
-   This is the usage guide for version 2 of the API. For version 1, see
-   :doc:`/reference/contrib/api/usage`
-
 The Wagtail API module exposes a public, read only, JSON-formatted API which
 can be used by external clients (such as a mobile app) or the site's frontend.
 

docs/reference/signals.rst

@@ -7,10 +7,7 @@ Wagtail's :ref:`page-revision-model-ref` and :ref:`page-model-ref` implement
 `Signals <https://docs.djangoproject.com/en/1.8/topics/signals/>`__ from ``django.dispatch``.
 Signals are useful for creating side-effects from page publish/unpublish events.
 
-Primarily, these are used by the :doc:`Frontend Cache <./contrib/frontendcache>` contrib module
-and the :doc:`./contrib/api/index`. You could also use signals to send
-publish notifications to a messaging service, or ``POST`` messages to another
-app that's consuming the API, such as a static site generator.
+For example, you could use signals to send publish notifications to a messaging service, or ``POST`` messages to another app that's consuming the API, such as a static site generator.
 
 
 page_published

docs/releases/1.0.rst

@@ -21,7 +21,7 @@ Wagtail API - A RESTful API for your Wagtail site
 
 When installed, the new Wagtail API module provides a RESTful web API to your
 Wagtail site. You can use this for accessing your raw field content for your
-sites pages, images and documents in JSON format. See :doc:`/reference/contrib/api/index`
+sites pages, images and documents in JSON format.
 
 
 MySQL support