Documentation: customTemplates

Change-Id: I9e1eb7f7ef3554730437ff225246af92bc52beee

Documentation/config.md

diff --git a/Documentation/config.md b/Documentation/config.md
index c24807b..79b53d8 100644
--- a/Documentation/config.md
+++ b/Documentation/config.md
@@ -47,6 +47,18 @@
 exportAll = true
 ```
 
+### Custom templating
+
+The web views are defined via Soy templates, you inject your own version which
+will be passed to the renderer. See `.soy` files in the source code for
+available templates
+
+```
+[gitiles]
+customTemplates = path/to/somefile.soy
+customTemplates = path/to/another.soy
+```
+
 ### Fixed time zone
 
 By default dates are formatted including the local user time zone as that