Offer a reformat feature

[kaotoio]

Offer a reformat feature

[igarashitm]

Aligning expression dialect would fall into here as well

- when:
    simple: ${header.foo} == 'foo'

 - when:
     simple:
       expression: '${header.foo} == 'foo'

 - when:
     expression:
       simple: ${header.foo} == 'foo'

 - when:
     expression:
       simple:
         expression: ${header.foo} == 'foo'

[lhein]

That isn't just a pure code formatting as the title might suggest. This is more of an optimize code feature.