write down 010-knitr-in-5mins.{md,html}

Squashed commit of the following:

commit 33da5a3520fe3fb9b66ba7e961ff5819c94a1827
Author: Yuu ISHIKAWA <yuu.ishikawa@gmail.com>
Date:   Wed Mar 19 11:03:47 2014 +0900

    update markdowon file

commit 345d00b80f0a54a66d389ab900fa07f69c02b3b4
Author: Yuu ISHIKAWA <yuu.ishikawa@gmail.com>
Date:   Wed Mar 19 10:58:25 2014 +0900

    update markdown file

commit b09bb5e9a020f1d4442cf8263917788967670572
Author: Yuu ISHIKAWA <yuu.ishikawa@gmail.com>
Date:   Wed Mar 19 09:43:36 2014 +0900

    update markdown file

commit 985822b9019aeb8a8d4ba4beeca7a25cd57dc380
Author: Yuu ISHIKAWA <yuu.ishikawa@gmail.com>
Date:   Wed Mar 19 09:28:46 2014 +0900

    update markdown file