[DOCS] Fix misspelling of "multiple" (#28257)

Author: snikch

docs/reference/migration/migrate_6_0/rest.asciidoc

@@ -63,7 +63,7 @@ mapping if it did not exist yet.
 ==== Indices information APIs
 
 Previously it was possible to execute `GET /_aliases,_mappings` or `GET
-/myindex/_settings,_alias` by separating mulitple types of requests with commas
+/myindex/_settings,_alias` by separating multiple types of requests with commas
 in order to retrieve multiple types of information about one or more indices.
 This comma-separation for retrieving multiple pieces of information has been
 removed.. `GET /_all` can be used to retrieve all aliases, settings, and