Update CODEOWNERS to include model-metadata (#1455)

Author: sbidari

.github/CODEOWNERS

@@ -1,9 +1,9 @@
-/src/* @sbidari @dylanhmorris @O957
 /.github/** @sbidari @dylanhmorris @O957
 /hub-config/* @sbidari @dylanhmorris @O957
 /auxiliary_data/weekly-model-submissions/ @sbidari @dylanhmorris @O957
 /model-output/CovidHub-baseline/ @sbidari @dylanhmorris @O957
 /model-output/CovidHub-ensemble/ @sbidari @dylanhmorris @O957
+/model-metadata/ @sbidari @dylanhmorris @O957
 README.md @sbidari @dylanhmorris @O957
 .pre-commit-config.yaml @sbidari @dylanhmorris @O957
 .gitignore @sbidari @dylanhmorris @O957