Add link to the FreeIPA Documentation page.

README

@@ -64,7 +64,10 @@ to be running.
 While in an ideal case the use of FreeIPA server container can simplify
 the setup, prior experience with FreeIPA is definitely useful. Getting
 the container set up and running can be also more challenging than
-other typical containerized workloads.
+other typical containerized workloads. Refer to
+[FreeIPA documentation](https://www.freeipa.org/page/Documentation.html);
+here we only focus on the aspects that are specific to running FreeIPA
+containerized.
 
 ### Running the container