Add documentation and JSON schema for .SRCINFO files

docs/repositories/source_repository.rst:
Explain .SRCINFO files in the context of the source repository and add
the JSON schema, which can be used to validate it.

docs/repositories/source_repository.rst

@@ -6,8 +6,8 @@ Source Repository
 
 A source repository is a |version control repository|, that contains the
 necessary files to build a package. At the bare minimum this includes a
-|PKGBUILD| file, but may contain an install script as well as patches or other
-arbitrary files.
+|PKGBUILD| and a ``.SRCINFO`` file, but may also contain an install script as
+well as patches or other arbitrary files.
 
 Using |makepkg|, the sources are used to build a package, which can be
 installed with |pacman|. With the help of |package splitting| it is possible to
@@ -18,6 +18,75 @@ create more than one package from a single |PKGBUILD|.
   Due to |dbscripts| and |makepkg| limitations it is currently not possible to
   target more than one :ref:`binary repository` with a single |PKGBUILD|.
 
+.. _srcinfo:
+
+.SRCINFO
+--------
+
+The ``.SRCINFO`` files contained in a :ref:`source repository` are data
+representations of the accompanying |PKGBUILD| files and as such describe the
+sources of any :ref:`package` build from it.
+
+The files are read and parsed and can be described by the :ref:`srcinfov1` JSON
+schema.
+
+.. _pkgbase section:
+
+Pkgbase section
+^^^^^^^^^^^^^^^
+
+This section of a ``.SRCINFO`` file describes the data common to all packages in
+the |PKGBUILD| (this is similar to how :ref:`outputpackagebase_schema`
+describes the data common to a set of packages in a :ref:`management
+repository`).
+
+The section is read and parsed when reading :ref:`srcinfo` files and must
+exist. It can be described by the :ref:`pkgbasesectionv1` JSON schema.
+
+.. _pkgname section:
+
+Pkgname section
+^^^^^^^^^^^^^^^
+
+This section of a ``.SRCINFO`` file describes the data of a single package in
+the |PKGBUILD|, which is different from the common data described by the
+:ref:`pkgbase section` (this is similar to how :ref:`outputpackage_schema`
+describes the data of a single package in a :ref:`management repository`).
+
+The section may occur multiple times, but must exist at least once. It is read
+and parsed when reading :ref:`srcinfo` files and can be described by the
+:ref:`pkgnamesectionv1` JSON schema.
+
+.. _srcinfo json schema:
+
+JSON schema
+^^^^^^^^^^^
+
+.. _srcinfov1:
+
+SrcInfoV1
+"""""""""
+
+.. literalinclude:: ../schema/SrcInfoV1.json
+   :language: json
+
+.. _pkgbasesectionv1:
+
+PkgBaseSectionV1
+""""""""""""""""
+
+.. literalinclude:: ../schema/PkgBaseSectionV1.json
+   :language: json
+
+.. _pkgnamesectionv1:
+
+PkgNameSectionV1
+""""""""""""""""
+
+.. literalinclude:: ../schema/PkgNameSectionV1.json
+   :language: json
+
+
 .. |version control repository| raw:: html
 
   <a target="blank" href="https://en.wikipedia.org/wiki/Repository_(version_control)">version control repository</a>