(Chore) docker installation method for fresns

[ife-adewunmi]

No description provided.

[mouyong]

Hello, @ife-adewunmi. Thank you for your efforts and contributions. Based on the following considerations, we do not recommend merging this PR at this time:

1. This PR directly updates the main program, Fresns root directory, and adds Dockerfile and other files in the root directory of the main program by default. Some users will not configure dockers and use them. So you can consider moving the relevant files to the deployment directory and providing containerized operation documents.

2. In your configuration, you have changed the default configuration of nginx. nginx itself has a default root directory, and it is not recommended to modify it for this reason. This will increase the problem of file management, configuration synchronization, and other issues.

3. The dockerfile and related files in this PR can be used for development environments, but are not suitable for production environments.

If you are interested, we can explore how to provide a containerized development and production environment for developers.