New viewer [#49] (#549)

app: Rewrite of PMTiles viewer (pmtiles.io) [#49, #551, #555, #556]

* Rewrite the app using SolidJS / Tailwind.
* Make the map view mobile friendly.
* Add an archive inspector for viewing the low level structure of PMTiles.
* Add a tile inspector for viewing a single tile in isolation. 
* Support TileJSON.
* Support raster archives.

app/README.md

@@ -1,4 +1,22 @@
-# Install
+## Usage
 
-* First go to the `/js` directory in the root of the PMTiles repository and `npm install`
-* `npm run dev` to start the app on port 3000
+```bash
+$ npm install
+```
+
+## Available Scripts
+
+In the project directory, you can run:
+
+### `npm run dev`
+
+Runs the app in the development mode.<br>
+Open [http://localhost:5173](http://localhost:5173) to view it in the browser.
+
+### `npm run build`
+
+Builds the app for production to the `dist` folder.<br>
+It correctly bundles Solid in production mode and optimizes the build for the best performance.
+
+The build is minified and the filenames include the hashes.<br>
+Your app is ready to be deployed!