Add disqus comments for provider documents

docs/providers/callable.rst

@@ -56,3 +56,6 @@ Delegation of :py:class:`Callable` providers is the same as
 :ref:`factory_providers_delegation` section for examples (with exception 
 about using :py:class:`DelegatedCallable` instead of 
 :py:class:`DelegatedFactory`).
+
+
+.. disqus::

docs/providers/custom.rst

@@ -33,3 +33,6 @@ Example:
 .. literalinclude:: ../../examples/providers/custom_factory.py
    :language: python
    :linenos:
+
+
+.. disqus::

docs/providers/external_dependency.rst

@@ -40,3 +40,6 @@ Example:
 .. literalinclude:: ../../examples/providers/external_dependency.py
    :language: python
    :linenos:
+
+
+.. disqus::

docs/providers/factory.rst

@@ -105,3 +105,6 @@ provided type:
 .. literalinclude:: ../../examples/providers/factory_provided_type.py
    :language: python
    :linenos:
+
+
+.. disqus::

docs/providers/object.rst

@@ -10,3 +10,6 @@ Example:
 .. literalinclude:: ../../examples/providers/object.py
    :language: python
    :linenos:
+
+
+.. disqus::

docs/providers/overriding.rst

@@ -44,3 +44,6 @@ Example:
 .. literalinclude:: ../../examples/providers/overriding_users_model.py
    :language: python
    :linenos:
+
+
+.. disqus::

docs/providers/singleton.rst

@@ -98,3 +98,6 @@ Example:
 .. literalinclude:: ../../examples/providers/singleton_thread_locals.py
    :language: python
    :linenos:
+
+
+.. disqus::