404 to example in readme

[mewmew]

The readme links to the minimal example application, however the link https://github.com/xlab/android-go/tree/master/example results in a 404. Note that other projects, such as https://github.com/golang-ui/nuklear, also refer to the old example app at that link. Thus is would be preferable either to restore the location of the minimal example such that the old link works, or update the link in both android-go, golang-ui/nuklear (and other repos referring to the old link).