Add nofification to admins after setup a new release

[vitormattos]

After setup a new LibreSign release, notify admins about the importance to help the project.

Other good point to do here is request to send a report with usage statistics like Nextcloud Server do after the server update.

Follow an example of notification after the update of Nextcloud server:

to-do

• Identify how to add this notification after LibreSign update
• Identify what type of data is collected from Nextcloud Server at this report and check what kind of data is possible be collected to send to LibreSign
• Create a purpose of text to add at notification and check if we will redirect to a page that will have contents about requesting funding to LibreSign.

[vitormattos]

This is made by this app:

https://github.com/nextcloud/survey_client/tree/master