Add docs for call in transaction (#70)

Co-authored-by: Stefano Ottolenghi <stefano.ottolenghi@neo4j.com>

Author: ConorNeo

modules/ROOT/pages/actions/begin-and-commit-a-transaction-in-one-request.adoc

@@ -3,8 +3,6 @@
 [[http-api-begin-and-commit-a-transaction-in-one-request]]
 = Begin and commit a transaction in one request
 
-== Begin and commit request
-
 If there is no need to keep a transaction open across multiple HTTP requests, you can begin a transaction, execute statements, and commit within a single HTTP request.
 
 _Example request_
@@ -50,4 +48,52 @@ _Example response_
 }
 ----
 
+It is also possible to send *+CALL IN TRANSACTION+* requests to this endpoint.
+
+_Example request_
+
+* *+POST+* +http://localhost:7474/db/neo4j/tx/commit+
+* *+Accept:+* +application/json;charset=UTF-8+
+* *+Content-Type:+* +application/json+
+
+[source, JSON, role="nocopy"]
+----
+{
+  "statements": [
+    {
+      "statement": "UNWIND [4, 2, 1, 0] AS i CALL { WITH i CREATE ()} IN TRANSACTIONS OF 2 ROWS RETURN i"
+    }
+  ]
+}
+----
+
+[WARNING]
+====
+If you send multiple statements (at least one being `CALL IN TRANSACTION`), and one of the normal
+statements fails, the `CALL IN TRANSACTION` query will *_not_* be rolled back, while the others will.
+In the example below, the simple `CREATE` statements would be rolled back in case of failure, but the `CALL IN TRANSACTION` would not.
+The final node count would thus be 4.
+====
 
+_Example request_
+
+* *+POST+* +http://localhost:7474/db/neo4j/tx/commit+
+* *+Accept:+* +application/json;charset=UTF-8+
+* *+Content-Type:+* +application/json+
+
+[source, JSON, role="nocopy"]
+----
+{
+  "statements": [
+    {
+      "statement": "UNWIND [4, 2, 1, 0] AS i CALL { WITH i CREATE ()} IN TRANSACTIONS OF 2 ROWS RETURN i"
+    },
+    {
+      "statement": "CREATE ()"
+    },
+    {
+      "statement": "CREATE ()"
+    }
+  ]
+}
+----