[DOCS] Add link to installation pages
[DOCS] Add link to installation pages

Original commit: elastic/x-pack-elasticsearch@6884bbe1de8e1d01cde9439d4eb37f415e47597b

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