documentation: fix links

content/pages/en/documentation.rst

@@ -22,10 +22,10 @@ Comprehensive documentation
 ===========================
 
 Docs for the latest stable version 5 are available online at
-`knot-resolver.cz/documentation/stable <stable>`__.
+`knot-resolver.cz/documentation/stable/ <stable/>`__.
 
 Docs for the latest early-access version 6.0.x are available online at
-`knot-resolver.cz/documentation/latest <https://knot-resolver.cz/documentation/latest>`__
+`knot-resolver.cz/documentation/latest/ <https://www.knot-resolver.cz/documentation/latest/>`__
 
 Offline documentation is also available in *knot-resolver-doc* package for most
 distributions.
@@ -52,10 +52,10 @@ Versions
 5.x (stable)
 ------------
 
-* `v5.7.2 <v5.7.2>`_
+* `v5.7.2 <v5.7.2/>`_
 
 6.x (early-access)
 ------------------
 
-* `v6.0.7 <v6.0.7>`_
-* `v6.0.6 <v6.0.6>`_
+* `v6.0.7 <v6.0.7/>`_
+* `v6.0.6 <v6.0.6/>`_