docs: remove leftover enter subcmd section
docs: remove leftover enter subcmd section

coreos/rkt,shobhit85/rkt,rkt/rkt,yifan-gu/rkt,akshaykarle/rkt,tmrts/rkt,intelsdi-x/rkt,s-urbaniak/rkt,jonboulle/rkt,lucasallan/rkt,markllama/rkt,sstabellini/rkt,cab105/rkt,ybubnov/rkt,sgotti/rkt,jjlakis/rkt,intelsdi-x/rkt,Wilybald/rkt,matthaias/rkt,nhlfr/rkt,sgotti/rkt,alban/rkt,Shashwatsh/rkt,Wilybald/rkt,jakon89/rkt,achanda/rkt,shobhit85/rkt,tmrts/rkt,ybubnov/rkt,squeed/rkt,jonboulle/rkt,mike1729/rkt,coreos/rkt,kinvolk/rkt,rkt/rkt,matthaias/rkt,jonboulle/rkt,rkt/rkt,sstabellini/rkt,akshaykarle/rkt,Shashwatsh/rkt,yifan-gu/rkt,mike1729/rkt,kinvolk/rkt,jjlakis/rkt,yifan-gu/rocket,monstermunchkin/rkt,yifan-gu/rocket,Wilybald/rkt,squeed/rkt,achanda/rkt,nhlfr/rkt,mike1729/rkt,joshix/rkt,euank/rkt,monstermunchkin/rkt,monstermunchkin/rkt,akshaykarle/rkt,yifan-gu/rkt,euank/rkt,kinvolk/rkt,lucasallan/rkt,euank/rkt,markllama/rkt,Shashwatsh/rkt,lucasallan/rkt,shobhit85/rkt,joshix/rkt,sstabellini/rkt,ybubnov/rkt,squeed/rkt,matthaias/rkt,Wilybald/rkt,s-urbaniak/rkt,lucasallan/rkt,markllama/rkt,jakon89/rkt,yifan-gu/rocket,jakon89/rkt,cab105/rkt,s-urbaniak/rkt,dgonyeo/rkt,alban/rkt,joshix/rkt,alban/rkt,joshix/rkt,dgonyeo/rkt,achanda/rkt,intelsdi-x/rkt,nhlfr/rkt,coreos/rkt,sgotti/rkt,tmrts/rkt,dgonyeo/rkt,rkt/rkt,kinvolk/rkt,cab105/rkt,jjlakis/rkt