chore: update documentation

README.md

@@ -1,35 +1,93 @@
 # ProtoMaps (PMTiles) Chart provider for Signal K server
 
-Signal K Node server `resource-provider` plugin enabling support for PMTiles map files.
+Signal K Node server `resource provider` plugin enabling the use of PMTiles map files.
 
-Read more about PMTiles here: [ProtoMaps](https://protomaps.com/docs/pmtiles)
-
-To convert MBTiles to PMTiles use the [go-pmtiles](https://github.com/protomaps/go-pmtiles/releases) utility.
+_**Note: Requires `Signal K` server running on `NodeJS` v18 or later!**_
 
+---
 
-### Usage
+PMTiles is a single-file archive for pyramids of tiled data that can be hosted on simple storage and does not require a database (eg. SQLite) to be installed.
 
-1. Install `signalk-pmtiles-plugin` from Appstore using Signal K server admin console
+Your MBTiles files can be easily converted to PMTiles using the [go-pmtiles](https://github.com/protomaps/go-pmtiles/releases) utility.
 
-1. Locate `PMTiles Chart provider` in **Plugin Config** screen
+Read more about PMTiles here: [ProtoMaps](https://protomaps.com/docs/pmtiles)
 
-1. Add "Chart paths" in plugin configuration. Defaults to `${signalk-configuration-path}/charts`
+---
 
-1. Place PMTiles chart files into configured path
+The plugin supports the Signal K server v2 Resources API and can be used in conjunction with other chart `resource provider` plugins.
 
-1. Enable plugin
+Chart metadata is made available to client apps via both v1 and v2 API paths.
 
-Chart metadata is available to client apps at the following paths:
+_Note: [Freeboard-SK](https://www.npmjs.com/package/@signalk/freeboard-sk) v2 or later supports the use of PMTiles charts._
 
 | Server Version | API | Path |
 |--- |--- |--- |
 | 1.x.x | v1 | `/signalk/v1/api/resources/charts` |
 | 2.x.x | v2 | `/signalk/v2/api/resources/charts` |
 
-_**Note: [Freeboard SK](https://www.npmjs.com/package/@signalk/freeboard-sk) v2 or later supports PMTiles charts.**_
+_Example: `/signalk/v2/api/resources/charts`_
+```JSON
+{
+	"kvarken.pmtiles": {
+		"identifier": "kvarken.pmtiles",
+		"name": "kvarken.pmtiles",
+		"description": "",
+		"type": "tilelayer",
+		"scale": 250000,
+		"minzoom": 3,
+		"maxzoom": 17,
+		"bounds": [17.899475, 62.6097716, 23.0905151, 63.8346133],
+		"format": "png",
+		"url": "/pmtiles/kvarken.pmtiles",
+		"layers": []
+	}
+}
+```
+
+_Example: `/signalk/v1/api/resources/charts`_
+```
+{
+	"kvarken.pmtiles": {
+		"identifier": "kvarken.pmtiles",
+		"name": "kvarken.pmtiles",
+		"description": "",
+		"type": "tilelayer",
+		"scale": 250000,
+		"minzoom": 3,
+		"maxzoom": 17,
+		"bounds": [17.899475, 62.6097716, 23.0905151, 63.8346133],
+		"format": "png",
+		"tilemapUrl": "/pmtiles/kvarken.pmtiles",
+		"chartLayers": []
+	}
+}
+```
+
+The plugin also creates a path from which map tile data is served `/pmtiles`.
+
+Visiting this url will display a list of discovered PMTiles files _(.pmtiles)_ in the location provided in the `Plugin Config` screen.  
+
+```
+["kvarken.pmtiles","NBottenv.pmtiles"]
+```
+
+---
+### Usage
+
+1. Install `signalk-pmtiles-plugin` from the **Appstore** screen in the Signal K server admin console
+
+1. Once installed, restart the server and the locate `PMTiles Chart provider` in the **Plugin Config** screen
+
+1. Enter the path to the folder in which you will store .pmtiles files in `Path to chart files`. _Note: If omitted the path will default to `.signalk/charts/pmtiles`_
+
+1. Click **Submit** to save the changes.
+
+1. Place your chart files _(.pmtiles)_ into folder entered in the previous step
+
+1. **Enable** plugin
 
 ---
 
 ## Sytem Requirements
 
-`Signal K` server running on `NodeJS` v18 (or later).
+- `Signal K` server running on `NodeJS` v18 (or later).