fix list indentation - mkdocs expects four spaces

docs/configuration.md

@@ -15,10 +15,10 @@ or applicable default will be utilized instead.
 - If you are running paperless on anything else, paperless will search
   for the configuration file in these locations and use the first one
   it finds:
-  - The environment variable `PAPERLESS_CONFIGURATION_PATH`
-  - `/path/to/paperless/paperless.conf`
-  - `/etc/paperless.conf`
-  - `/usr/local/etc/paperless.conf`
+    - The environment variable `PAPERLESS_CONFIGURATION_PATH`
+    - `/path/to/paperless/paperless.conf`
+    - `/etc/paperless.conf`
+    - `/usr/local/etc/paperless.conf`
 
 ## Required services