Add configurable update time for Docker version

[chavan-arvind]

Fixes #440

Add configuration for scheduled updates in Docker version.

• Dockerfile

  • Add UPDATE_CRON environment variable to allow custom cron schedules.
  • Modify the RUN command to use the UPDATE_CRON variable for setting the cron jobs.

• config/config.ini

  • Add a new setting update_cron for specifying the cron schedule.

• docs/tutorial.md

  • Update the documentation to explain how to configure the update time or interval for the Docker version.

• docs/tutorial_en.md

  • Update the documentation to explain how to configure the update time or interval for the Docker version.

[Guovin]

Well done, you've done what I planned to do. The docker container startup also seems to be missing code to read the update_cron configuration in config.ini. I am also optimizing docker related code recently, and I will merge it with your code after I improve it, thank you.

[Guovin]

Please push your code to the dev branch, thanks

[Guovin]

This implementation is no longer available for the current version