Changed the README from .rdoc to .md

Did this manually so I think I got most of the conversion right.

Fixes #607

Squashed commit of the following:

commit e0cbf22b35e08aba053d19674ed6295bd6b71ced
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Sun Jan 20 06:16:26 2013 +0530

    Removed the <li> tag for the markdown template list

commit f999620eac07b0b970b7b2ea42d4386f1dc83097
Merge: 95ab367 eed4f71
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Sun Jan 20 06:06:39 2013 +0530

    Merge branch 'master' of git://github.com/sinatra/sinatra

commit 95ab3673ece8996991fef505e3a3556f8c06e49f
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Fri Jan 11 07:53:31 2013 +0530

    Fixed a typo

commit 90a335049b711ee7fc1915616cf13bd926539ee6
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Fri Jan 11 07:44:22 2013 +0530

    <pre> tags break the whole layout. Replacing them with <tt> tags

commit e47cfff420c8e07b8b04c1ac4cab85ba9b78ca53
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Fri Jan 11 07:18:10 2013 +0530

    <pre> tags break the whole layout. Testing out <tt> tags

commit 40f59da1f4d52fda5018bf91a9a317f52113a116
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Fri Jan 11 06:59:02 2013 +0530

    Added the html definition lists

commit 63a18c478c61d3c88ecd67a42fcca001deff8ea2
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Fri Jan 11 03:39:57 2013 +0530

    Testing out some HTML in Markdown

commit 8d9442be525e909acd1f5b5c1bd4972c8bf810b2
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Thu Jan 10 01:14:16 2013 +0530

    Trying out code blocks instead of Rdoc tables

commit 766c80f1af854e03161192fadec3edf6e5093eaa
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Thu Jan 10 00:40:48 2013 +0530

    Fixed some more errors.

commit 2e9dc82a5a246007a4976db95b4608212c50841b
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Thu Jan 10 00:39:25 2013 +0530

    Fixed some more errors.

commit f12333bcd3515f63b3c998da98cf1e8b68bc01f9
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Thu Jan 10 00:33:47 2013 +0530

    Fixed a typo and finished the conversion.

commit 72830645c0dc235f62ccf1f1ffc8d8deaf39519d
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Thu Jan 10 00:31:52 2013 +0530

    First walkthrough done.

commit a43f41fab945ac9dece1f7ee95a29526c6d7c25d
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Wed Jan 9 22:32:34 2013 +0530

    First walkthrough done.

commit eb73fe095f191dc7c7bae2acdbfce436ba21f1e3
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Wed Jan 9 22:24:59 2013 +0530

    testing blockquote

commit 3cb91c48286f308de144b763e51aebdb02f034ad
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Wed Jan 9 22:19:21 2013 +0530

    testing blockquote

commit ae9119393e7d463c2916074ff47e5af0b316ec82
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Wed Jan 9 21:49:19 2013 +0530

    testing blockquote

commit 64a659c731036474435eb57349afe17bfde7a801
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Wed Jan 9 21:48:02 2013 +0530

    testing blockquote

commit 8d718ef1aa1b558cf052768b0ced13cf102d0639
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Wed Jan 9 21:42:17 2013 +0530

    testing blockquote

commit 0b16fc50d868f77f0ecaeeed9177dcf412d7d5d3
Author: Kashyap <kashyap.kmbc@gmail.com>
Date:   Wed Jan 9 21:37:55 2013 +0530

    rdoc to md conversion in progress

Signed-off-by: Konstantin Haase <konstantin.mailinglists@googlemail.com>