fix indentation in yaml example
fix indentation in yaml example

Previously was not valid yaml. The 'image' and 'run' attributes have to be inline with 'name'. Also replaced tabs with spaces in the example, but that was just tidying up since when copying and pasting from the README the tabs weren't transferred.
jesper/crane,stajkowski/crane,t-suwa/crane,t-suwa/crane,dreamcat4/crane,inthroxify/crane,michaelsauter/crane,stajkowski/crane,bjaglin/crane,inthroxify/crane,tmc/crane,rmoorman/crane,bjaglin/crane,dreamcat4/crane,rmoorman/crane,michaelsauter/crane,jesper/crane,tmc/crane