Improve environment variable usage documentation

[aaro-n]

Describe the error

I have completely read the Chinese installation document of Answer. I need to add a more complete description of the AUTO_INSTALL setting in environment variables. If there is no docker volumes mapping, when using environment variables for Answer installation, delete the Answer to run the container. And run the Answer container again, Answer will populate the database again, but the database already has content, Answer will prompt an error (the config.yaml file is missing, and the database uses postgresql).

Reappear

Set AUTO_INSTALL to true according to the document, and the installation will be automatically successful. The data has been written to the database. At this time, Answer can be accessed normally. After deleting the running container and using the same parameters, Answer will write the configuration to the database again. information, but the same configuration information already exists in postgresql.

Expected behavior

AnswerYou can use environment variables for parameter configuration and run, no configuration file is required.

[LinkinStars]

@aaro-n First of all, AUTO_INSTALL is only used for the first installation. After the installation is complete, you should not set this environment variable to true anymore. About If there is no docker volumes mapping. If you are just using Answer this is not fitting because not only the configuration file, but also the cache and uploaded images and other information are put here, so it is better to need to have the volumes. Of course, about your point about not using configuration files at all and using only environment variables, this is something that we will consider. Thanks for the feedback.