Update olap-engines.md (#5226)

* Update olap-engines.md

Missing Pinot in available OLAP engines,

* Update multiple-olap.md

fixing page numbers on OLAP engines dropdown

* Create connectors.md

Create OLAP engine reference guide that sits at the bottom of the /reference/project-files

docs/docs/reference/olap-engines/multiple-olap.md

@@ -2,7 +2,7 @@
 title: Using Multiple OLAP Engines
 description: Using multiple OLAP Engines to power dashboards in the same project
 sidebar_label: Using Multiple OLAP Engines
-sidebar_position: 4
+sidebar_position: 5
 ---
 
 ## Overview

docs/docs/reference/olap-engines/olap-engines.md

@@ -19,6 +19,7 @@ If there's an OLAP engine that you'd like to use with Rill but don't see it belo
 - [DuckDB (default)](duckdb.md) 
 - [Druid](druid.md)
 - [ClickHouse](clickhouse.md)
+- [Pinot](pinot.md)
 
 ## Reference
 

docs/docs/reference/project-files/connectors.md

@@ -0,0 +1,63 @@
+---
+title: Connector YAML
+sidebar_label: Connector YAML 
+sidebar_position: 70
+hide_table_of_contents: true
+---
+
+
+When you add olap_connector to your rill.yaml file, you will need to set up a `<connector_name>.yaml` file in the 'connectors' directory. This file requires the following parameters,`type` and `driver` (see below for more parameter options). Rill will automatically test the connectivity to the OLAP engine upon saving the file. This can be viewed in the connectors tab in the UI.
+
+:::tip Did you know?
+
+You can have multiple OLAP engines in a single project and have each dashboard run on a different engine using the olap_connector parameter directly on a dashboard.
+
+:::
+
+
+## Properties
+
+**`type`** - refers to the resource type and must be connector
+
+**`driver`** - refers to the OLAP engine
+
+- _`duckdb`_   link to [ DuckDB Documentation](https://duckdb.org/docs/guides/overview.html)
+- _`clickhouse`_ link to[ Clickhouse documentation](https://clickhouse.com/docs/en/intro)
+- _`druid`_ link to[ Druid documentation](https://druid.apache.org/docs/latest/design/)
+- _`pinot`_ link to[ Pinot documentation](https://docs.pinot.apache.org/)
+
+**`host`** - refers the hostname for your OLAP engine
+
+**`port`** - refers the port for your OLAP engine
+
+**`username`** - the username, in plaintext
+
+**`password`** - the password, in plaintext
+
+**`ssl`** - depending on the engine, this parameter may be required (_pinot_)
+
+
+You can also connect using a dsn parameter. You cannot use the above parameters along with the **`dsn`** parameter.
+
+**`dsn`** - connection string containing all the details above, in a single string. Note that each engine's syntax is slightly different. Please refer to [our documentation](https://docs.rilldata.com/reference/olap-engines/) for further details.
+
+---
+
+_Example #1: Connecting to a local running Clickhouse server (no security enabled)_
+```yaml
+type: connector
+driver: clickhouse
+
+host: "localhost"
+port: "9000"
+```
+
+_Example #2: Connecting to a ClickHouse Cloud _
+```yaml
+type: connector
+driver: clickhouse
+
+
+dsn: "https://<hostname>:<port>?username=<username>&password=<password>&secure=true&skip_verify=true"
+
+```