Adding more information to the overview lists of integrations (#11068)

docs/system-admin-guide/integrations/README.md

@@ -13,6 +13,9 @@ If you have previously worked with other tools and want to switch or need an int
 
 > **Note**:  We do not guarantee error-free and seamless use of the Community plugins. Installation and use is at your own risk.
 
+## Excel
+
+Find out more about the [Excel synchronization with OpenProject](./excel-synchronization).
 
 ## GitHub
 
@@ -29,20 +32,18 @@ Currently, there is no direct integration between OpenProject and Jira. Since Op
 
 If you would like to learn more about the features of **OpenProject vs Jira** please read [here](https://www.openproject.org/blog/open-source-jira-alternative/).
 
+## Mattermost
+
+There is a user-provided integration with Mattermost. Please note that it is not officially supported and that we do not take any liability when you use it. You can find it [here](https://github.com/girish17/op-mattermost).
+
 ## Microsoft Project
 
 There is an integration between MS Project and OpenProject. However, the synch plugin is not actively maintained at this time. If you wish to find out more, please [contact us](https://www.openproject.org/contact/).
 To synchronize tasks from MS Project to OpenProject, you can export your MS Project file to Excel and then [synchronize it with OpenProject]( ./excel-synchronization/).
 
-## Trello
+## Nextcloud
-
-Currently, there is no direct integration between OpenProject and Trello. To synchronize tasks from Trello to OpenProject, export your tasks from Trello into an Excel file and then import these tasks via an [Excel plugin into OpenProject](./excel-synchronization).
-
-If you would like to learn more about OpenProject's features vs Trello, please read [here](https://www.openproject.org/blog/trello-alternative/).
-
-## Toggl
 
-We do offer an integration between OpenProject and the time tracking app Toggl. Find out more [here](../../user-guide/time-and-costs/time-tracking/toggl-integration/).
+OpenProject offers a Nextcloud integration. You can find more information about the [set-up of the integration with Nextcloud](./nextcloud) and the [use of the Nextcloud plugin](../../user-guide/nextcloud-integration/).
 
 ## Slack
 
@@ -50,8 +51,15 @@ There is a rudimentary OpenProject Slack integration from the community. It mess
 To activate it in the Enterprise cloud please [get in touch](https://www.openproject.org/contact/). For the Enterprise on-premises edition and the Community Edition you can find the plugin and its documentation on GitHub: [OpenProject Slack plugin](https://github.com/opf/openproject-slack) 
 
 ## Timesheet
+
 Currently, there is no direct integration between OpenProject and Timesheet. If you are looking for a time tracking tool with a simple push of a button, consider the integration with [Toggl](../../user-guide/time-and-costs/time-tracking/toggl-integration/).
 
-## Mattermost
+## Toggl
 
-There is a user-provided integration with Mattermost. Please note that it is not officially supported and that we do not take any liability when you use it. You can find it [here](https://github.com/girish17/op-mattermost).
+We do offer an integration between OpenProject and the time tracking app Toggl. Find out more [here](../../user-guide/time-and-costs/time-tracking/toggl-integration/).
+
+## Trello
+
+Currently, there is no direct integration between OpenProject and Trello. To synchronize tasks from Trello to OpenProject, export your tasks from Trello into an Excel file and then import these tasks via an [Excel plugin into OpenProject](./excel-synchronization).
+
+If you would like to learn more about OpenProject's features vs Trello, please read [here](https://www.openproject.org/blog/trello-alternative/).