chore: init frontend-source directory with tooling scaffold

Former-commit-id: 435fb8e3e4f8e334ad3b0e95052edbdd9547d197

frontend-source/scripts/node_modules/editorconfig/lib/cli.d.ts

@@ -0,0 +1,14 @@
+import { type OutputConfiguration } from 'commander';
+import * as editorconfig from './';
+/**
+ * Command line interface for editorconfig.  Pulled out into a separate module
+ * to make it easier to test.
+ *
+ * @param args Usually process.argv.  Note that the first two parameters are
+ * usually 'node' and 'editorconfig'
+ * @param testing If testing, you may pass in a Commander OutputConfiguration
+ * so that you can capture stdout and stderror.  If `testing` is provided,
+ * this routine will throw an error instead of calling `process.exit`.
+ * @returns An array of combined properties, one for each file argument.
+ */
+export default function cli(args: string[], testing?: OutputConfiguration): Promise<editorconfig.Props[]>;