Update readme and add licensing stuff.

LICENSING.md

@@ -0,0 +1,26 @@
+# Licensing
+
+The license for this project is [AGPL-3.0](LICENSE.md).
+
+Specifically, the source code in directories `pkg` and `src` are derived from the Elasticsearch plugin code present in [Grafana repository]([https://](https://github.com/grafana/grafana)) as described below.
+
+## pkg (Go)
+
+The source code in `pkg` is derived from [Grafana repository][pkg/tsdb/elasticsearch](https://github.com/grafana/grafana/tree/main/pkg/tsdb/elasticsearch).
+
+To support the Quickwit API, the following changes were made:
+- Remove index pattern code.
+- Fix a [bug](https://github.com/quickwit-oss/quickwit-datasource/commit/c09f92128c7198ef0d44eaddf26a8c0b78a5149c) for nested term aggregations.
+- Adapt timestamp parsing to Quickwit's format.
+
+
+## src (TypeScript)
+
+The source code in `src` is derived from [Grafana repository][public/app/plugins/datasource/elasticsearch](https://github.com/grafana/grafana/tree/main/public/app/plugins/datasource/elasticsearch).
+
+To support the Quickwit API, the following changes were made:
+- Disable aggregations that Quickwit does not support.
+- Remove index pattern related code.
+- Remove `LegacyQueryRunner.ts`.
+- Remove `tracking.ts`.
+- Update the code to make it work outside of Grafana.

README.md

@@ -8,14 +8,15 @@ The Quickwit data source plugin allows you to query and visualize Quickwit data
 
 ## Special thanks and a note on the license
 
-This plugin is heavily inspired by the `elasticsearch` plugin available on the [Grafana repository](https://github.com/grafana/). So first of all, huge thanks to the Grafana team for open-sourcing all their work.
+This plugin is **heavily** inspired by the `elasticsearch` plugin available on the [Grafana repository](https://github.com/grafana/). First of all, huge thanks to the Grafana team for open-sourcing all their work.
 
-Also, we choose to put the plugin under `AGPL-3.0` as the Grafana repository is under this same license.
+It's more or less a fork of this plugin to adapt the code to Quickwit API. See [LICENSING](LICENSING.md) for details on the license and the changes made.
 
+The license for this project is [AGPL-3.0](LICENSE.md), and a [notice](NOTICE.md) was added to respect the Grafana Labs license.
 
 ## Version compatibility
 
-Grafana v9.5 is recommended as the data source was only tested on this version.
+We recommand Grafana v9.5 or v10.
 
 ## Installation