add flag for auto fetch and update instance from https://github.com/zedeus/nitter/wiki/instances

[dezhishen]

Change log

auto fetch and update instance from zedeus/nitter/wiki/instances,only public

• with flag -"auto-instances" true
• with env REPO_PROXY to request wiki's page by proxy

  change go version to 1.19

  change docker build step to make docker image less size

• docker build . -f Dockerfile.zh -t ... to use go proxy

[derat]

Thank you for sending a PR. Unfortunately, I'm uncomfortable with adding a lot of new dependencies (and code that I will need to maintain) in order to parse the GitHub page listing the Nitter instances. I'd be happy to accept a change that adds a small, separate program (a shell or Python script seems like it would be ideal) that prints the list of instances so it can be inserted in a command line. For example, it could be used like this:

nitter-rss-proxy -instances "$(./list-public-instances.sh)"

What do you think?

Also, I'd be happy to accept the Dockerfile change to reduce the image size if you upload it as a separate PR. (Thanks for doing this! I'm pretty unfamiliar with Docker and don't use it much myself.)