Add PWA example for PSPDFKit integration

- Created a new Progressive Web Application (PWA) example project demonstrating the integration of PSPDFKit for Web.
- Added essential files including package.json, README.md, and configuration files for PWA setup.
- Implemented a basic layout with a PDF viewer using PSPDFKit, including file upload functionality and offline capabilities.
- Included scripts for building and running the application, along with asset copying for necessary PSPDFKit files.
- Added sample assets including a PDF document and various icons for PWA.
- Introduced .gitignore to exclude unnecessary files and directories.
- Provided detailed instructions in the README for getting started and running the example.

Author: ritz078

.gitignore

@@ -6,4 +6,7 @@ playwright-report
 pspdfkit-lib/
 
 open-iconic
-.next/
+.next/
+.nuxt/
+dist/
+analytics.js

examples/pwa/.gitignore

@@ -0,0 +1,2 @@
+dist
+node_modules

examples/pwa/LICENSE

@@ -0,0 +1,42 @@
+The PSPDFKit Sample applications are licensed with a modified BSD
+license. In plain language: you're allowed to do whatever you wish
+with the code, modify, redistribute, embed in your products (free or
+commercial), but you must include copyright, terms of usage and
+disclaimer as stated in the license.
+
+You will require a commercial PSPDFKit License to run these examples
+in non-demo mode. Please refer to [email protected] for details.
+
+Copyright © 2018-present PSPDFKit GmbH.
+All rights reserved.
+
+Redistribution and use in source or binary forms,
+with or without modification, are permitted provided
+that the following conditions are met:
+
+- Redistributions of source code must retain the above copyright
+  notice, this list of conditions and the following disclaimer.
+
+- Redistributions in binary form must reproduce the above copyright
+  notice, this list of conditions and the following disclaimer in the
+  documentation and/or other materials provided with the
+  distribution.
+
+- Redistributions of PSPDFKit Samples must include attribution to
+  PSPDFKit, either in documentation or other appropriate media.
+
+- Neither the name of the PSPDFKit, PSPDFKit GmbH, nor its developers
+  may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

examples/pwa/README.md

@@ -0,0 +1,85 @@
+# Nutrient Web SDK Example - PWA
+
+This example shows how to integrate [Nutrient Web SDK](https://www.nutrient.io/web/) and create a PWA (Progressive Web App).
+
+You can check out a live preview here: [www.nutrient.io/pwa](https://www.nutrient.io/pwa/).
+
+This sample application features a basic PWA setup including a [manifest](src/manifest.js) and a [service worker](src/serviceWorker.js), to allow your app to function offline as well as an [IndexedDB storage](src/scripts/PSPDFKitFileStorage.js) for PDFs. This way, your files are persisted even after you close the browser.
+
+In this example we use [workbox](https://github.com/GoogleChrome/workbox), a popular PWA framework by Google.
+
+## Prerequisites
+
+- [Node.js](http://nodejs.org/)
+- A Nutrient Web SDK license. If you don't already have one you can [request a free trial here](https://www.nutrient.io/try/).
+
+## Support, Issues and License Questions
+
+PSPDFKit offers support for customers with an active SDK license via https://www.nutrient.io/support/request/
+
+Are you [evaluating our SDK](https://www.nutrient.io/try/)? That's great, we're happy to help out! To make sure this is fast, please use a work email and have someone from your company fill out our sales form: https://www.nutrient.io/sales/
+
+## Getting Started
+
+Clone the repo:
+
+```bash
+git clone https://github.com/PSPDFKit/pspdfkit-web-example-pwa.git
+cd pspdfkit-web-example-pwa
+```
+
+Install the project dependencies with `npm`:
+
+```bash
+npm install
+```
+
+Now that everything is installed we need to configure the app to use our [Nutrient Web SDK license key](https://www.nutrient.io/guides/web/current/standalone/integration).
+
+Edit `./config/license-key` and replace the string `YOUR_LICENSE_KEY_GOES_HERE` with the license key that you received via e-mail.
+
+## Running the Example
+
+We are ready to launch the app! 🎉
+
+To run the app in development mode:
+
+```bash
+npm run start
+```
+
+## Build Production Artifacts
+
+To build a production version, just follow the above guide but instead of running `start`:
+
+```bash
+npm run build
+```
+
+The build script will then create a file called `./dist` which you can copy to your webserver as-is.
+
+## How it works
+
+Under `./src` you can find a simple application shell that loads Nutrient Web SDK.
+
+The application uses a [service worker](src/serviceWorker.js) to provide offline support and pre-caching for the majority of the assets.
+
+To reduce the amount of boilerplate, we use [workbox](https://github.com/GoogleChrome/workbox) - a library from Google that abstracts away some of the verbosity associated to the service worker creation and configuration.
+
+We also use workbox-cli, another library from Google, to automatically generate a Manifest file for our ServiceWorker pre-cache when we run `npm start`. You can find this configuration file in [`./src/workbox-config.js`](src/workbox-config.js).
+
+To allow PDFs to be persisted locally so they do not need to be downloaded again, we've created the [`PSPDFKitFileStore`](src/scripts/PSPDFKitFileStore.js) library. It uses a lightweight and `Promise`-based wrapper around the IndexedDB API called [`idb`](https://github.com/jakearchibald/idb) under the hood. The code is designed to work independently of the PWA example and can also be used in Internet Explorer 11.
+
+## Mobile Support
+
+If you try to connect to the local development server remotely you'll quickly see that the PWA is not working as expected. This is due to the fact that the PWA APIs [require a valid SSL/TLS certificate](https://developers.google.com/web/progressive-web-apps/checklist) to properly function and you will probably not have this setup locally.
+
+For a better experience, we suggest you check out the [hosted PWA example](https://www.nutrient.io/pwa/) or deploy a production build to your own server.
+
+## License
+
+This software is licensed under a [modified BSD license](LICENSE).
+
+## Contributing
+
+Please ensure [you have signed our CLA](https://www.nutrient.io/guides/web/current/miscellaneous/contributing/) so that we can accept your contributions.