Update Readme with information about fork about woodpecker

[laszlocph]

Thanks for the issue.

I think to best answer this question, head over to https://github.com/laszlocph/drone-oss-08/blob/master/vendor/vendor.json where all the dependencies are listed.

On top of that

• all github.com/drone/ repos have been forked, although references were not updated in the vendor file.
• some dependencies were pulled in the project to allow faster iteration: #12
• maybe difficult to find it in the vendor file, the UI is hosted here: https://github.com/laszlocph/drone-ui

I added some info on the project in this PR. #30

[laszlocph]

I keep this issue open as the Readme.md is far from what it should be.