Add deprecation warnings for ignore_malformed to reference docs

docs/reference/query-dsl/geo-bounding-box-query.asciidoc

@@ -52,6 +52,9 @@ Then the following simple query can be executed with a
 |Option |Description
 |`_name` |Optional name field to identify the filter
 
+|`ignore_malformed` |deprecated[5.0.0,Use `validation_method` instead] Set to `true` to
+accept geo points with invalid latitude or longitude (default is `false`).
+
 |`validation_method` |Set to `IGNORE_MALFORMED` to
 accept geo points with invalid latitude or longitude, set to
 `COERCE` to also try to infer correct latitude or longitude. (default is `STRICT`).

docs/reference/query-dsl/geo-distance-query.asciidoc

@@ -162,6 +162,11 @@ The following are options allowed on the filter:
 
     Optional name field to identify the query
 
+`ignore_malformed`::
+   
+    deprecated[5.0.0,Use `validation_method` instead] Set to `true` to accept geo points with invalid latitude or
+    longitude (default is `false`).
+
 `validation_method`::
 
     Set to `IGNORE_MALFORMED` to accept geo points with invalid latitude or

docs/reference/query-dsl/geo-polygon-query.asciidoc

@@ -34,6 +34,9 @@ points. Here is an example:
 |Option |Description
 |`_name` |Optional name field to identify the filter
 
+|`ignore_malformed` |deprecated[5.0.0,Use `validation_method` instead] Set to `true` to accept geo points with invalid latitude or
+longitude (default is `false`).
+
 |`validation_method` |Set to `IGNORE_MALFORMED` to accept geo points with
 invalid latitude or longitude, `COERCE` to try and infer correct latitude
 or longitude, or `STRICT` (default is `STRICT`).