added server.host to dev guide (opensearch-project#917)

* added server.host to dev guide

Signed-off-by: kohinoor98 <kohinoorchatterjee1998@gmail.com>

* emp server.host and moved command to Test section

Signed-off-by: kohinoor98 <kohinoorchatterjee1998@gmail.com>

---------

Signed-off-by: kohinoor98 <kohinoorchatterjee1998@gmail.com>

DEVELOPER_GUIDE.md

@@ -5,6 +5,7 @@
   - [Build](#build)
   - [Run](#run)
   - [Test](#test)
+  - [Backport](#backport)
 
 ## Developer guide
 
@@ -57,6 +58,13 @@ In the base OpenSearch Dashboards directory, run
 
 ### Test
 
+- `yarn start --no-base-path --no-watch --server.host="0.0.0.0"`
+
+  Starts OpenSearch Dashboards and includes this plugin. This setup is necessary for running tests using `Cypress` on `localhost:5601`.
+
+  **Important:** The `--server.host="0.0.0.0"` parameter is crucial as it configures the server to accept connections from any IP address, which is necessary for `Cypress` to connect to the dashboard server.
+
+
 - `yarn test:jest`
 
   - Runs the plugin tests.