Adding README.source.

Signed-off-by: Daniel Baumann <daniel@debian.org>

debian/README.source

@@ -0,0 +1,37 @@
+Package Repositories
+--------------------
+
+Backports for the current stable debian distribution as well as snapshots of
+unreleased versions may be available in repositories listed on the maintainers
+homepage. The current URL of the maintainer homepage can be seen in
+debian/copyright.
+
+
+Source Access
+-------------
+
+You can obtain the sources of this package with:
+
+  $ apt-get source ${PACKAGE}
+
+whereas '${PACKAGE}' has to be replaced with the actual name of the package.
+
+This package is maintained with the Git version control system. The current git
+source tree can be obtained with:
+
+  $ git clone ${GIT_URI}
+
+whereas '${GIT_URI}' has to be replaced with the actual URI for the Git
+repository. The current Git URI can be seen in debian/control in the extracted
+package sources.
+
+More information about Git can be found in the git-core package.
+
+This package may use the Quilt patch system to manage all modifications to the
+upstream source. Changes, if any, are stored in the source package as diffs in
+debian/diff and are applied during the build. Current modifications can be
+applied to the source tree with:
+
+  $ quilt push -a
+
+More information about Quilt can be found in the quilt package.