Ensure all source code files contain SPDX licence

lib/index.d.ts

@@ -1,17 +1,30 @@
 /**
- * Type definitions originally lifted from `@types/sharp`, MIT-licensed.
- * https://opensource.org/licenses/MIT
+ * Copyright 2017 François Nguyen and others.
  *
- * Original definition authors:
- *  - Wooseop Kim <https://github.com/wooseopkim>
- *  - Bradley Odell <https://github.com/BTOdell>
- *  - Jamie Woodbury <https://github.com/JamieWoodbury>
- *  - Floris de Bijl <https://github.com/Fdebijl>
- *  - Billy Kwok <https://github.com/billykwok>
- *  - Espen Hovlandsdal <https://github.com/rexxars>
- *  - Adam Kwiatek <https://github.com/akwiatek>
+ * Billy Kwok <https://github.com/billykwok>
+ * Bradley Odell <https://github.com/BTOdell>
+ * Espen Hovlandsdal <https://github.com/rexxars>
+ * Floris de Bijl <https://github.com/Fdebijl>
+ * François Nguyen <https://github.com/phurytw>
+ * Jamie Woodbury <https://github.com/JamieWoodbury>
+ * Wooseop Kim <https://github.com/wooseopkim>
+ *
+ * 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.
  */
 
+// SPDX-License-Identifier: MIT
+
 /// <reference types="node" />
 
 import { Duplex } from 'stream';