fix xref between peer .md files

docs/labels.md

@@ -11,7 +11,7 @@ Each object can have a set of key/value labels defined.  Each Key must be unique
 }
 ```
 
-We'll eventually index and reverse-index labels for efficient queries and watches, use them to sort and group in UIs and CLIs, etc. We don't want to pollute labels with non-identifying, especially large and/or structured, data. Non-identifying information should be recorded using [annotations](/docs/annotations.md).
+We'll eventually index and reverse-index labels for efficient queries and watches, use them to sort and group in UIs and CLIs, etc. We don't want to pollute labels with non-identifying, especially large and/or structured, data. Non-identifying information should be recorded using [annotations](annotations.md).
 
 
 ## Motivation