Add stylelint dependency

This also adds CC-BY-4.0 to the list of accepted licenses.

DISABLE_THIRD_PARTY_CHECK=update dependencies

Bug: chromium:1083142
Change-Id: I8612de2fba52dae32eeb71af79d5aacfde52142b
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2220097
Reviewed-by: Paul Lewis <aerotwist@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
diff --git a/node_modules/indent-string/index.js b/node_modules/indent-string/index.js
new file mode 100644
index 0000000..e1ab804
--- /dev/null
+++ b/node_modules/indent-string/index.js
@@ -0,0 +1,35 @@
+'use strict';
+
+module.exports = (string, count = 1, options) => {
+	options = {
+		indent: ' ',
+		includeEmptyLines: false,
+		...options
+	};
+
+	if (typeof string !== 'string') {
+		throw new TypeError(
+			`Expected \`input\` to be a \`string\`, got \`${typeof string}\``
+		);
+	}
+
+	if (typeof count !== 'number') {
+		throw new TypeError(
+			`Expected \`count\` to be a \`number\`, got \`${typeof count}\``
+		);
+	}
+
+	if (typeof options.indent !== 'string') {
+		throw new TypeError(
+			`Expected \`options.indent\` to be a \`string\`, got \`${typeof options.indent}\``
+		);
+	}
+
+	if (count === 0) {
+		return string;
+	}
+
+	const regex = options.includeEmptyLines ? /^/gm : /^(?!\s*$)/gm;
+
+	return string.replace(regex, options.indent.repeat(count));
+};