[editorial] Normalized intra-spec link in protocol/file-exporter.md (#4366)

- Contributes to
open-telemetry/opentelemetry.io#5935
- Normalized intra-spec link in `file-exporter.md`: there is no need to
have the path step out of the spec only to step back into it

/cc @arminru @svrnm

Author: chalin

specification/protocol/file-exporter.md

@@ -4,7 +4,7 @@ linkTitle: File Exporter
 
 # OpenTelemetry Protocol File Exporter
 
-**Status**: [Development](../../specification/document-status.md)
+**Status**: [Development](../document-status.md)
 
 This document provides a placeholder for specifying an OTLP exporter capable of
 exporting to either a file or stdout.