Add documentation for Armada schemas

This is to add documentation for Armada schemas that are
used for validating Chart, ChartGroup and Manifest documents.

Change-Id: If7bbc6a8c174ab15c553a278003f827337e2b860

docs/source/operations/index.rst

@@ -10,12 +10,13 @@ Operations Guide
    :maxdepth: 2
    :caption: Contents:
 
-   guide-api.rst
+   guide-api
-   guide-build-armada-yaml.rst
+   guide-build-armada-yaml
-   guide-configure.rst
+   guide-configure
-   guide-troubleshooting.rst
+   guide-troubleshooting
-   guide-use-armada.rst
+   guide-use-armada
+   validation
    exceptions/index
-   guide-helm-plugin.rst
+   guide-helm-plugin
-   sampleconf.rst
+   sampleconf
-   samplepolicy.rst
+   samplepolicy

docs/source/operations/validation.rst

@@ -0,0 +1,71 @@
+..
+  Copyright 2018 AT&T Intellectual Property.
+  All Rights Reserved.
+
+  Licensed under the Apache License, Version 2.0 (the "License"); you may
+  not use this file except in compliance with the License. You may obtain
+  a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+  License for the specific language governing permissions and limitations
+  under the License.
+
+.. _validation:
+
+===================
+Document Validation
+===================
+
+Validations
+===========
+
+Armada, like other UCP components, uses ``jsonschema`` to validate documents
+passed to it. This includes dedicated schemas for ``Chart``, ``ChartGroup``
+and ``Manifest``.
+
+Validation Schemas
+==================
+
+Below are the schemas Armada uses to validate documents.
+
+Armada Schemas
+--------------
+
+* Chart schema.
+
+  Chart schema against which all Armada ``Chart`` documents are validated.
+
+  .. literalinclude:: ../../../armada/schemas/armada-chart-schema.yaml
+    :language: yaml
+    :lines: 15-
+    :caption: Armada Chart schema.
+
+  This schema is used to sanity-check all ``Chart`` documents.
+
+* ChartGroup schema.
+
+  ChartGroup schema against which all Armada ``ChartGroup`` documents are
+  validated.
+
+  .. literalinclude:: ../../../armada/schemas/armada-chartgroup-schema.yaml
+    :language: yaml
+    :lines: 15-
+    :caption: Armada ChartGroup schema.
+
+  This schema is used to sanity-check all ``ChartGroup`` documents.
+
+* Manifest schema.
+
+  Manifest schema against which all Armada ``Manifest`` documents are
+  validated.
+
+  .. literalinclude:: ../../../armada/schemas/armada-manifest-schema.yaml
+    :language: yaml
+    :lines: 15-
+    :caption: Armada Manifest schema.
+
+  This schema is used to sanity-check all ``Manifest`` documents.