Added execution context example. Fixed #306

docs/Makefile

@@ -223,3 +223,7 @@ dummy:
 	$(SPHINXBUILD) -b dummy $(ALLSPHINXOPTS) $(BUILDDIR)/dummy
 	@echo
 	@echo "Build finished. Dummy builder generates no files."
+
+.PHONY: livehtml
+livehtml:
+	sphinx-autobuild -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html

docs/execution/index.rst

@@ -2,6 +2,38 @@
 Execution
 =========
 
+For executing a query a schema, you can directly call the ``execute`` method on it.
+
+
+.. code:: python
+    
+    schema = graphene.Schema(...)
+    result = schema.execute('{ name }')
+
+``result`` represents he result of execution. ``result.data`` is the result of executing the query, ``result.errors`` is ``None`` if no errors occurred, and is a non-empty list if an error occurred.
+
+
+Context
+_______
+
+You can pass context to a query via ``context_value``.
+
+
+.. code:: python
+
+    class Query(graphene.ObjectType):
+        name = graphene.String()
+
+        def resolve_name(self, args, context, info):
+            return context.get('name')
+    
+    schema = graphene.Schema(Query)
+    result = schema.execute('{ name }', context_value={'name': 'Syrus'})
+
+
+Middleware
+__________
+
 .. toctree::
    :maxdepth: 1