Update docs

Author: marcusolsson

website/docs/jsonata.md

@@ -0,0 +1,10 @@
+---
+id: jsonata
+title: JSONata
+---
+
+[JSONata](https://docs.jsonata.org/) is a query and transformation language for JSON data.
+
+If you're new to JSONata, start by looking at some [simple queries](https://docs.jsonata.org/simple).
+
+[Dashboard variables](https://grafana.com/docs/grafana/latest/variables/) are available as JSONata variables, e.g. `$instanceName`. Since dashboard variables can have multiple values, the JSONata variable is always an array. If your variable contains a single value, you can use `$instanceName[0]` to index the first value in the array.

website/docs/query-editor.md

@@ -13,7 +13,7 @@ The query editor for the JSON API data source consists of a number of tabs. Each
 
 The **Fields** tab is where you select the data to extract from the JSON document returned by the URL configured in the data source configuration.
 
-- **Field** must contain a valid [JSONPath](./jsonpath.md) expression and can return one or more elements.
+- **Field** lets you define a query expression that determines the data to extract from the JSON document. There are two supported query languages: [JSONPath](./jsonpath.md) and [JSONata](./jsonata.md).
 - **Type** defines the JSON type of the elements returned by the **Field** expression. By default, Grafana uses the types in the JSON document. If **Type** is set to a different type than the original property type, Grafana tries to parse the value.
 - **Alias** overrides the default name of the field.
 

website/sidebars.js

@@ -29,6 +29,10 @@ module.exports = {
       type: 'doc',
       id: 'jsonpath',
     },
+    {
+      type: 'doc',
+      id: 'jsonata',
+    },
     {
       type: 'doc',
       id: 'troubleshooting',