[DOCS] Add ML info_content functions (elastic/x-pack-elasticsearch#1354)
[DOCS] Add ML info_content functions (elastic/x-pack-elasticsearch#1354)

Original commit: elastic/x-pack-elasticsearch@5cfa9618b57781b6b55129bfad5670d5634093e4

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