https://github.com/rubygems/rubygems/commit/573ffad3ea

For synopsis, subcommand and flag documentation like other commands do.

https://github.com/rubygems/rubygems/commit/f528029756

The `bundle list` command is a convenient way for human to know what gems and versions are available. By introducing a `--format=json` option, we can provide the same information to machines in a stable format that is robust to UI additions or modifications. It indirectly supports  `Gemfile.lock` modifications by discouraging external tools from attempting to parse that format.

This addition allows for the scripting of installation tools, such as buildpacks, that wish to branch logic based on gem versions. For example:

```ruby
require "json"

command = "bundle list --format=json"
output = `#{command}`
raise "Command `#{command}` errored: #{output}" unless $?.success?

railties = JSON.parse(output).find {|gem| gem["name"] == railties }
if railties && Gem::Version.new(railties["version"]) >= Gem::Version.new("7")
  puts "Using Rails greater than 7!"
end
```

The top level is an object with a single key, "gems", this structure allows us to add other information in the future (should we desire) without having to change the json schema.

https://github.com/rubygems/rubygems/commit/9e081b0689

There already different ways of toggling off this behavior, like setting
`bundle config clean false`, or configuring Bundler to install to system
gems with `bundle config path.system true`.

https://github.com/rubygems/rubygems/commit/6daa09f60a

https://github.com/rubygems/rubygems/commit/3e4687616a

https://github.com/rubygems/rubygems/commit/9ed20bddab

https://github.com/rubygems/rubygems/commit/591d2c0503

We switched to nronn because ronn-ng felt abandoned, but it seems
it has activity again, so switch back.

https://github.com/rubygems/rubygems/commit/8288cfd3e0