Use SDPX license headers, ensure they are preserved in builds

This
- Moves the license out of the qrcodegen src file and into a standalone
LICENSE
- Adds copyright & spdx license headers to src files (https://spdx.dev/ids/)
- Ensures license headers are preserved in the build output

src/index.tsx

@@ -1,3 +1,9 @@
+/**
+ * @license qrcode.react
+ * Copyright (c) Paul O'Shannessy
+ * SPDX-License-Identifier: ISC
+ */
+
 import React, {useRef, useEffect} from 'react';
 import type {CSSProperties} from 'react';
 import qrcodegen from './third-party/qrcodegen';

src/third-party/LICENSE

@@ -0,0 +1,22 @@
+QR Code generator library (TypeScript)
+
+Copyright (c) Project Nayuki.
+https://www.nayuki.io/page/qr-code-generator-library
+
+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.

src/third-party/qrcodegen/index.ts

@@ -1,24 +1,7 @@
-/*
- * QR Code generator library (TypeScript)
- *
- * Copyright (c) Project Nayuki. (MIT License)
- * https://www.nayuki.io/page/qr-code-generator-library
- *
- * 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.
+/**
+ * @license QR Code generator library (TypeScript)
+ * Copyright (c) Project Nayuki.
+ * SPDX-License-Identifier: MIT
  */
 
 "use strict";

tsup.config.ts

@@ -0,0 +1,7 @@
+import {defineConfig} from 'tsup';
+
+export default defineConfig({
+  esbuildOptions(options) {
+    options.legalComments = 'inline';
+  },
+});