[DOCS] reworded to prevent code span rendering glitch (#25442)

Changed `rescore`s to `rescore` requests as an backtick followed by the s character appears to be interpreted as an apostrophe  which then leads to an unbalanced backtick for the next code span in the remainder of the paragraph

Closes #25443

docs/reference/index-modules.asciidoc

@@ -120,7 +120,7 @@ specific index module:
 
 `index.max_rescore_window`::
 
-    The maximum value of `window_size` for `rescore`s in searches of this index.
+    The maximum value of `window_size` for `rescore` requests in searches of this index.
     Defaults to `index.max_result_window` which defaults to `10000`. Search
     requests take heap memory and time proportional to
     `max(window_size, from + size)` and this limits that memory.