Issue description

The current nginx.conf configuration file for apache apisix is generated by bin/apisix from the config.yaml configuration file, so nginx.conf is best generated by the bin/apisix script rather than maintaining a copy itself.

However, the current bin/apisix support for generating nginx.conf is a generic configuration and does not support some custom or temporary configurations.

It is hoped that config.yaml will add an annotation field and that the configuration of this part will be generated directly to the specified location in nginx.conf.

Similar practice: in kubernetes-ingress, Ingress configuration has a comment field, where you can fill in large nginx.conf custom configurations directly in the comment field, instead of having to implement a piece of code for each field (because some configurations are customized, and it doesn't make sense to leave them to bin/apisix implementation, which is not general enough).

Environment

• apisix version (cmd: apisix version):
• OS: