[DOCS] Reformats cluster pending tasks API (#45280)
[DOCS] Reformats cluster pending tasks API (#45280)

Co-Authored-By: James Rodewig <1808b47fd52c0582c136bfc1e6304b3e5fc3a95c@elastic.co>
gingerwizard/elasticsearch,gingerwizard/elasticsearch,robin13/elasticsearch,robin13/elasticsearch,gingerwizard/elasticsearch,HonzaKral/elasticsearch,gingerwizard/elasticsearch,scorpionvicky/elasticsearch,GlenRSmith/elasticsearch,scorpionvicky/elasticsearch,coding0011/elasticsearch,scorpionvicky/elasticsearch,scorpionvicky/elasticsearch,nknize/elasticsearch,uschindler/elasticsearch,GlenRSmith/elasticsearch,HonzaKral/elasticsearch,coding0011/elasticsearch,robin13/elasticsearch,coding0011/elasticsearch,scorpionvicky/elasticsearch,coding0011/elasticsearch,nknize/elasticsearch,gingerwizard/elasticsearch,gingerwizard/elasticsearch,nknize/elasticsearch,uschindler/elasticsearch,robin13/elasticsearch,uschindler/elasticsearch,GlenRSmith/elasticsearch,nknize/elasticsearch,HonzaKral/elasticsearch,nknize/elasticsearch,coding0011/elasticsearch,GlenRSmith/elasticsearch,gingerwizard/elasticsearch,uschindler/elasticsearch,GlenRSmith/elasticsearch,uschindler/elasticsearch,HonzaKral/elasticsearch,robin13/elasticsearch