GitHub Clone with Proxy Settings

1. Set your proxy config
`git config --global http.proxy http://proxyuser:proxypwd@proxy.server.com:8080`
2. Clone the repo
`git clone https://github.com/githubteacher/devs-may-2016`

The issue only lists git config and git clone commands; first verify whether it is intended as a documentation update or a report of a cloning problem. No target file, expected change, or completion criterion is provided, so clarify those before editing.

索引モデルが issue の本文から書いたものです。