Add a note as to Dockerfile support being a power-user feature
Add a note as to Dockerfile support being a power-user feature

Closes #2067

[ci skip]

econya/dokku,sseemayer/dokku,claytonbrown/dokku,sseemayer/dokku,jimjag/dokku,amaltson/dokku,alexquick/dokku,fruitl00p/dokku,johnfraney/dokku,sseemayer/dokku,Evlos/dokku,progrium/dokku,amaltson/dokku,elia/dokku,alexquick/dokku,sseemayer/dokku,claytonbrown/dokku,fruitl00p/dokku,amaltson/dokku,alexquick/dokku,johnfraney/dokku,expa/dokku,codeconfab/dokku,Evlos/dokku,alexquick/dokku,fruitl00p/dokku,sseemayer/dokku,jimjag/dokku,fruitl00p/dokku,amaltson/dokku,claytonbrown/dokku,fruitl00p/dokku,alexquick/dokku,jimjag/dokku,elia/dokku,Evlos/dokku,alexquick/dokku,codeconfab/dokku,johnfraney/dokku,expa/dokku,amaltson/dokku,claytonbrown/dokku,claytonbrown/dokku,elia/dokku,johnfraney/dokku,expa/dokku,Evlos/dokku,claytonbrown/dokku,jimjag/dokku,johnfraney/dokku,claytonbrown/dokku,elia/dokku,codeconfab/dokku,codeconfab/dokku,alexquick/dokku,econya/dokku,econya/dokku,econya/dokku,progrium/dokku,elia/dokku,fruitl00p/dokku,dokku/dokku,dokku/dokku,fruitl00p/dokku,sseemayer/dokku,amaltson/dokku,codeconfab/dokku,expa/dokku,johnfraney/dokku,econya/dokku,Evlos/dokku,jimjag/dokku,johnfraney/dokku,elia/dokku,dokku/dokku,econya/dokku,jimjag/dokku,amaltson/dokku,fruitl00p/dokku,dokku/dokku,Evlos/dokku,expa/dokku,codeconfab/dokku,dokku/dokku,progrium/dokku,jimjag/dokku,johnfraney/dokku,sseemayer/dokku,progrium/dokku,progrium/dokku,codeconfab/dokku,expa/dokku,progrium/dokku,dokku/dokku,codeconfab/dokku,econya/dokku,amaltson/dokku,expa/dokku,progrium/dokku,alexquick/dokku,Evlos/dokku,elia/dokku,sseemayer/dokku,dokku/dokku,claytonbrown/dokku,dokku/dokku,Evlos/dokku,expa/dokku,jimjag/dokku,econya/dokku,elia/dokku,progrium/dokku