Initial Sphinx-based documentation templates and infra

Change-Id: I180ad109b8a885df6fd8911729289cee5c9bd99f
diff --git a/.gitreview b/.gitreview
new file mode 100644
index 0000000..faaf342
--- /dev/null
+++ b/.gitreview
@@ -0,0 +1,5 @@
+[gerrit]
+host=gerrit.onosproject.org
+port=29418
+project=trellis-docs.git
+defaultremote=origin