Monorepo-style tags break latest release detection

还没有人认领这个 Issue。

The mapbox-gl-native repository uses [a non-semver-compliant tag naming scheme](https://github.com/mapbox/mapbox-gl-native/wiki/Versions-and-tagging) that prepends a platform identifier to an otherwise semver-compliant version number, since the various libraries developed in that monorepo are versioned independently. This tool relies on the `latest-semver` package, which is unable to understand these version numbers on its own:

https://github.com/mapbox/github-release-tools/blob/8d88e10b6fedf3f34f8d3929287148088e65709c/src/get-latest-release.js#L13

Fortunately, I think we can make the tool compatible with mapbox-gl-native by filtering tags by platform and stripping off the platform identifiers before calling `latestSemver()`. The tool would need a new command line option to specify a platform.

/cc @anandthakker

从 src/get-latest-release.js 和 issue 中链接的 latest-semver 调用开始。跟踪命令行选项的解析方式，然后确定平台过滤和前缀移除应放在哪里。当平台选项能够让工具从 mapbox-gl-native-style 标签中识别最新 release，且不破坏现有标签处理时，即表示完成。

由索引模型根据 Issue 内容生成。