[DOCS] More edits for ML Getting Started (elastic/x-pack-elasticsearch#1238)
[DOCS] More edits for ML Getting Started (elastic/x-pack-elasticsearch#1238)

Original commit: elastic/x-pack-elasticsearch@69be11bfd2ce74983f4fe999666be336dcd9ef57

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