Add copyright notice to chronic_duration.js and chronic_duration_spec.js

Issue: https://gitlab.com/gitlab-com/legal-and-compliance/-/issues/677

app/assets/javascripts/chronic_duration.js

@@ -4,6 +4,37 @@
  * https://gitlab.com/gitlab-org/gitlab-chronic-duration/-/blob/master/lib/gitlab_chronic_duration.rb.
  */
 
+/*
+ * This code is based on code from
+ * https://gitlab.com/gitlab-org/gitlab-chronic-duration and is
+ * distributed under the following license:
+ *
+ * MIT License
+ *
+ * Copyright (c) Henry Poydar
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
 export class DurationParseError extends Error {}
 
 // On average, there's a little over 4 weeks in month.

spec/frontend/chronic_duration_spec.js

@@ -4,6 +4,37 @@
  * https://gitlab.com/gitlab-org/gitlab-chronic-duration/-/blob/master/spec/lib/chronic_duration_spec.rb.
  */
 
+/*
+ * This code is based on code from
+ * https://gitlab.com/gitlab-org/gitlab-chronic-duration and is
+ * distributed under the following license:
+ *
+ * MIT License
+ *
+ * Copyright (c) Henry Poydar
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
 import {
   parseChronicDuration,
   outputChronicDuration,