Add JSON export docs

src/content/docs/export/json.md

@@ -0,0 +1,32 @@
+---
+title: Export to JSON
+---
+
+The `COPY TO` clause can export query results to a JSON file. To use this feature, you have to install the
+JSON extension using the instructions shown [here](/extensions/json).
+
+To demonstrate this, we will create a node table and insert some data into it.
+```sql
+CREATE NODE TABLE Person (id SERIAL, name STRING, info STRUCT(height DOUBLE, age INT64, previous_usernames STRING[]), PRIMARY KEY(id));
+```
+```cypher
+CREATE (:Person {name: "Alice", info: {height: 1.68, age: 45, previous_usernames: ["alice123", "alice_34425"]}});
+CREATE (:Person {name: "Bob", info: {height: 1.81, age: 71, previous_usernames: ["the_builder", "the_minion"]}});
+CREATE (:Person {name: "Gregory", info: {height: 1.73, age: 22, previous_usernames: ["gregory7"]}});
+```
+
+The following query will export the data from the `Person` node table to a JSON file.
+```sql
+COPY (MATCH (p:Person) RETURN p.*) TO 'people-output.json';
+```
+Result:
+
+```json
+[
+{"p.id":0,"p.name":"Alice","p.info":{"height":1.68,"age":45,"previous_usernames":["alice123","alice_34425"]}},
+{"p.id":1,"p.name":"Bob","p.info":{"height":1.81,"age":71,"previous_usernames":["the_builder","the_minion"]}},
+{"p.id":2,"p.name":"Gregory","p.info":{"height":1.73,"age":22,"previous_usernames":["gregory7"]}}
+]
+```
+
+You can use a JSON formatter to make the output more readable.