Change docs links to actual file extension (.md)

See https://gerrit-review.googlesource.com/83950 for detailed context.

Change-Id: I4dc35b6396b57f70f659d4a458011b08817d8719

src/main/resources/Documentation/cmd-export.md

diff --git a/src/main/resources/Documentation/cmd-export.md b/src/main/resources/Documentation/cmd-export.md
index 7f4351d..011e51a 100644
--- a/src/main/resources/Documentation/cmd-export.md
+++ b/src/main/resources/Documentation/cmd-export.md
@@ -3,7 +3,7 @@
 
 NAME
 ----
-@PLUGIN@ export - Export successful reviews to [refs/notes/review](refs-notes-review.html)
+@PLUGIN@ export - Export successful reviews to [refs/notes/review](refs-notes-review.md)
 
 SYNOPSIS
 --------