Add URL to initctl reference

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

README.md

@@ -44,7 +44,7 @@ Example
 This example `/etc/finit.conf` can also be split up in multiple `.conf`
 files in `/etc/finit.d`.  Available, but not yet enabled, services can
 be placed in `/etc/finit.d/available` and enabled by an operator using
-the `initctl` tool.
+the [initctl](#commands--status) tool.
 
 ```conf
 # Fallback if /etc/hostname is missing