docs: standardize and validate plugin READMEs

prismlauncher-instances/README.md

@@ -1,6 +1,34 @@
 # PrismLauncher Instances
-![prismlauncher instances thumbnail](thumbnail.webp)
-**PrismLauncher Instances** is a plugin that adds PrismLauncher instances to the noctalia launcher.
+
+PrismLauncher Instances adds your local Minecraft instances to the Noctalia
+launcher so they can be searched and started directly.
+
+## Plugin
+
+| Field | Value |
+| --- | --- |
+| ID | `radimous/prismlauncher-instances` |
+| Entry | Launcher provider: `prismlauncher-instances` |
+| Launcher Prefix | `/pl` |
 
 ## Requirements
-- [prismlauncher](https://github.com/PrismLauncher/PrismLauncher)
+
+Install [PrismLauncher](https://github.com/PrismLauncher/PrismLauncher) and make
+sure the `prismlauncher` command is available on `PATH`.
+
+## Usage
+
+Open the Noctalia launcher and type `/pl` to list all detected PrismLauncher
+instances. Continue typing to filter by instance name, then activate a result
+to launch that instance with `prismlauncher --launch`.
+
+## Settings
+
+| Setting | Type | Default | Description |
+| --- | --- | --- | --- |
+| `prism_path` | `string` | `~/.local/share/PrismLauncher` | PrismLauncher data directory containing its configuration and instances. |
+
+## Notes
+
+The provider reads `prismlauncher.cfg`, instance metadata, and local instance
+icons from the configured PrismLauncher directory. It does not modify them.