[Sugar-devel] Update docs

[Simon Schampijer]

Hi,

the docs have been updated for the 'osbuild'-change [1]. The 
documentation pointed to by our README [2] is not [3].

Do we have a new documentation url already? /me lost track

Cheers,
    Simon

[1] https://github.com/sugarlabs/sugar-docs/blob/master/build.md
[2] http://sugarlabs.org/~buildbot/docs/build.html
[3] http://sugarlabs.org/~buildbot/docs/build.html