[DOCS] Added setup-passwords command parameters (elastic/x-pack-elasticsearch#2735)
[DOCS] Added setup-passwords command parameters (elastic/x-pack-elasticsearch#2735)

* [DOCS] Added setup-passwords command parameters

* [DOCS] Addressed feedback in setup-passwords command

Original commit: elastic/x-pack-elasticsearch@5401994c56bc8616a412cc53f8bf36ec41fccbd0

coding0011/elasticsearch,robin13/elasticsearch,gfyoung/elasticsearch,uschindler/elasticsearch,HonzaKral/elasticsearch,gingerwizard/elasticsearch,gingerwizard/elasticsearch,robin13/elasticsearch,gfyoung/elasticsearch,uschindler/elasticsearch,coding0011/elasticsearch,HonzaKral/elasticsearch,gingerwizard/elasticsearch,robin13/elasticsearch,coding0011/elasticsearch,gingerwizard/elasticsearch,uschindler/elasticsearch,nknize/elasticsearch,gfyoung/elasticsearch,scorpionvicky/elasticsearch,nknize/elasticsearch,scorpionvicky/elasticsearch,scorpionvicky/elasticsearch,GlenRSmith/elasticsearch,gfyoung/elasticsearch,uschindler/elasticsearch,GlenRSmith/elasticsearch,HonzaKral/elasticsearch,HonzaKral/elasticsearch,gingerwizard/elasticsearch,GlenRSmith/elasticsearch,gingerwizard/elasticsearch,GlenRSmith/elasticsearch,robin13/elasticsearch,gingerwizard/elasticsearch,GlenRSmith/elasticsearch,coding0011/elasticsearch,scorpionvicky/elasticsearch,coding0011/elasticsearch,uschindler/elasticsearch,gfyoung/elasticsearch,nknize/elasticsearch,robin13/elasticsearch,scorpionvicky/elasticsearch,nknize/elasticsearch,nknize/elasticsearch