[DOCS] Document JVM node stats (#49500)
[DOCS] Document JVM node stats (#49500)

* [DOCS] Document JVM node stats

Documents the `jvm` parameters returned by the `_nodes/stats` API.

Co-Authored-By: James Baiera <1bfa9a2032a871afc84e03abc01fe51877568fba@gmail.com>

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