[DOCS] Escape commas in experimental[] for Asciidoctor migration (#41578)

Author: jrodewig

docs/reference/search/rank-eval.asciidoc

@@ -1,7 +1,7 @@
 [[search-rank-eval]]
 == Ranking Evaluation API
 
-experimental[The ranking evaluation API is experimental and may be changed or removed completely in a future release, as well as change in non-backwards compatible ways on minor versions updates. Elastic will take a best effort approach to fix any issues, but experimental features are not subject to the support SLA of official GA features.]
+experimental["The ranking evaluation API is experimental and may be changed or removed completely in a future release, as well as change in non-backwards compatible ways on minor versions updates. Elastic will take a best effort approach to fix any issues, but experimental features are not subject to the support SLA of official GA features."]
 
 The ranking evaluation API allows to evaluate the quality of ranked search
 results over a set of typical search queries. Given this set of queries and a