docs/about, docs/extension-point: fix broken links

Linking to .md or .html works either way when used from a Gerrit
instance, but linking to .md makes the link work when browsing the
document in Gitiles.

The libModule link in extension-point.md was just wrong. This change
makes the link work when used in a Gerrit instance.

Change-Id: I44806523cb8e4aec8393c1fcc36aba4a78c37e66
diff --git a/src/main/resources/Documentation/about.md b/src/main/resources/Documentation/about.md
index d216366..b0382af 100644
--- a/src/main/resources/Documentation/about.md
+++ b/src/main/resources/Documentation/about.md
@@ -17,7 +17,7 @@
 share is mounted to which the repositories should be replicated.
 
 It is possible to
-[configure](config.html#configuring-cluster-replication) the plugin so
+[configure](config.md#configuring-cluster-replication) the plugin so
 that multiple primaries share the replication work approximately evenly.
 
 Replication of account data (NoteDb)
diff --git a/src/main/resources/Documentation/extension-point.md b/src/main/resources/Documentation/extension-point.md
index 076aded..83e7e45 100644
--- a/src/main/resources/Documentation/extension-point.md
+++ b/src/main/resources/Documentation/extension-point.md
@@ -2,7 +2,7 @@
 ==============
 
 The replication plugin exposes an extension point to allow influencing its behaviour from another plugin or a script.
-Extension points can be defined from the replication plugin only when it is loaded as [libModule](/config-gerrit.html#gerrit.installModule) and
+Extension points can be defined from the replication plugin only when it is loaded as [libModule](../../../Documentation/config-gerrit.html#gerrit.installModule) and
 implemented by another plugin by declaring a `provided` dependency from the replication plugin.
 
 ### Install extension libModule