Update gantt chart dashboards plugin link to GitHub (#6328)

* Update gantt chart dashboards plugin link

Signed-off-by: Melissa Vagi <[email protected]>

* Update plugins.md

Signed-off-by: Melissa Vagi <[email protected]>

---------

Signed-off-by: Melissa Vagi <[email protected]>

Author: vagimeli

_install-and-configure/install-dashboards/plugins.md

@@ -36,7 +36,7 @@ The following table lists available OpenSearch Dashboards plugins.
 | Anomaly Detection Dashboards | [anomaly-detection-dashboards-plugin](https://github.com/opensearch-project/anomaly-detection-dashboards-plugin) | 1.0.0 |
 | Custom Import Maps Dashboards | [dashboards-maps](https://github.com/opensearch-project/dashboards-maps) | 2.2.0 |
 | Search Relevance Dashboards | [dashboards-search-relevance](https://github.com/opensearch-project/dashboards-search-relevance) | 2.4.0 |
-| Gantt Chart Dashboards | [gantt-chart](https://github.com/opensearch-project/dashboards-visualizations/tree/main/gantt-chart) | 1.0.0 |
+| Gantt Chart Dashboards | [gantt-chart](https://github.com/opensearch-project/dashboards-visualizations) | 1.0.0 |
 | Index Management Dashboards | [index-management-dashboards-plugin](https://github.com/opensearch-project/index-management-dashboards-plugin) | 1.0.0 |
 | Notebooks Dashboards | [dashboards-notebooks](https://github.com/opensearch-project/dashboards-notebooks) | 1.0.0 |
 | Notifications Dashboards | [dashboards-notifications](https://github.com/opensearch-project/dashboards-notifications) | 2.0.0 |