chore(AIP-202): fix broken link (#1429)

Author: paladin-devops

aip/general/0129.md

@@ -75,7 +75,7 @@ means returning the value unchanged, with one exception:
 ### Normalizations
 
 A field that is normalized by the service **must** be annotated with the
-`google.api.field_info` extension. See [AIP-202](aip-202) for guidance on using
+`google.api.field_info` extension. See ([AIP-202][]) for guidance on using
 this extension The allowed set of normalizations includes the following formats:
 
 * uuid