chore: do not commit openapi schema files

Author: zone117x

.gitignore

@@ -129,3 +129,7 @@ yarn.lock
 #rosetta-cli results
 rosetta-output-construction/rosetta-cli-output-const.json
 rosetta-output/rosetta-cli-output.json
+
+# doc schema
+docs/openapi.json
+docs/openapi.yaml