Add homebrew api mirroring environment variables support

HOMEBREW_API_DOMAIN:                       {
    description:  "Use this URL as the download mirror for Homebrew JSON API. " \
                  "If metadata files at that URL are temporarily unavailable, " \
                  "the default API domain will be used as a fallback mirror.",
    default_text: "`https://formulae.brew.sh/api`.",
    default:      [HOMEBREW_API_DEFAULT_DOMAIN](https://docs.brew.sh/rubydoc/top-level-namespace.html#HOMEBREW_API_DEFAULT_DOMAIN-constant),
  },
HOMEBREW_BOTTLE_DOMAIN:                    {
    description:  "Use this URL as the download mirror for bottles. " \
                  "If bottles at that URL are temporarily unavailable, " \
                  "the default bottle domain will be used as a fallback mirror. " \
                  "For example, `export HOMEBREW_BOTTLE_DOMAIN=http://localhost:8080` will cause all bottles " \
                  "to download from the prefix `http://localhost:8080/`. " \
                  "If bottles are not available at `$HOMEBREW_BOTTLE_DOMAIN` " \
                  "they will be downloaded from the default bottle domain.",
    default_text: "`https://ghcr.io/v2/homebrew/core`.",
    default:      [HOMEBREW_BOTTLE_DEFAULT_DOMAIN](https://docs.brew.sh/rubydoc/top-level-namespace.html#HOMEBREW_BOTTLE_DEFAULT_DOMAIN-constant),
  }

 export HOMEBREW_BOTTLE_DOMAIN="https://mirrors.ustc.edu.cn/homebrew-bottles"
 export HOMEBREW_API_DOMAIN="https://mirrors.ustc.edu.cn/homebrew-bottles/api"