(Minor) Fix some typos (#36180)

docs/reference/mapping/types/parent-join.asciidoc

@@ -46,7 +46,7 @@ PUT my_index/_doc/1?refresh
 
 PUT my_index/_doc/2?refresh
 {
-  "text": "This is a another question",
+  "text": "This is another question",
   "my_join_field": {
     "name": "question"
   }
@@ -417,7 +417,7 @@ The mapping above represents the following tree:
                                  |
                                 vote
 
-Indexing a grand child document requires a `routing` value equals
+Indexing a grandchild document requires a `routing` value equals
 to the grand-parent (the greater parent of the lineage):
 
 
@@ -436,4 +436,4 @@ PUT my_index/_doc/3?routing=1&refresh <1>
 // TEST[continued]
 
 <1> This child document must be on the same shard than its grand-parent and parent
-<2> The parent id of this document (must points to an `answer` document)
+<2> The parent id of this document (must points to an `answer` document)