Update DEVELOPER_GUIDE.md

Co-authored-by: Miki <[email protected]>
Signed-off-by: Kawika Avilla <[email protected]>

DEVELOPER_GUIDE.md

@@ -282,7 +282,7 @@ This method can also be used to develop against the [full distribution of OpenSe
 
 _This step is only mandatory if you have the [`security` plugin](https://github.com/opensearch-project/security) installed on your OpenSearch cluster with https/authentication enabled._
 
-> 1. Run `export initialAdminPassword=<inital admin password>` since its needed by the configuration script
+> 1. Run `export initialAdminPassword=<initial admin password>` since it's needed by the configuration script
 > 2. Run `yarn opensearch snapshot --security`
 > 3. Wait a few seconds while the plugin is installed, configured, and OpenSearch starts up.