Refine geo-point and geo-shape docs (elastic#90913) (elastic#91136)

* Refine geo-point and geo-shape docs

While reviewing the docs for another issue, some deprecated
references to prefix-trees were discovered, leading to interest
in bringing the docs a little more up-to-date.

* Update docs/reference/mapping/types/geo-point.asciidoc

Co-authored-by: Abdon Pijpelink <[email protected]>

* Update docs/reference/mapping/types/geo-shape.asciidoc

Co-authored-by: Abdon Pijpelink <[email protected]>

Co-authored-by: Abdon Pijpelink <[email protected]>
(cherry picked from commit c19f642)

Co-authored-by: Craig Taverner <[email protected]>

Author: abdonpijpelink

docs/reference/mapping/types/geo-point.asciidoc

@@ -8,9 +8,12 @@ Fields of type `geo_point` accept latitude-longitude pairs, which can be used:
 
 * to find geopoints within a <<query-dsl-geo-bounding-box-query,bounding box>>,
   within a certain <<query-dsl-geo-distance-query,distance>> of a central point,
-  or within a <<query-dsl-geo-polygon-query,polygon>> or within a <<query-dsl-geo-shape-query,`geo_shape` query>>.
-* to aggregate documents <<search-aggregations-bucket-geohashgrid-aggregation,geographically>>
-  or by <<search-aggregations-bucket-geodistance-aggregation,distance>> from a central point.
+  or within a <<query-dsl-geo-shape-query,`geo_shape` query>> (for example, points in a polygon).
+* to aggregate documents by <<search-aggregations-bucket-geodistance-aggregation,distance>> from a central point
+* to aggregate documents by geographic grids: either
+  <<search-aggregations-bucket-geohashgrid-aggregation,`geo_hash`>>,
+  <<search-aggregations-bucket-geotilegrid-aggregation,`geo_tile`>> or
+  <<search-aggregations-bucket-geohexgrid-aggregation,`geo_hex`>>.
 * to integrate distance into a document's <<query-dsl-function-score-query,relevance score>>.
 * to <<geo-sorting,sort>> documents by distance.
 

docs/reference/mapping/types/geo-shape.asciidoc

@@ -5,18 +5,28 @@
 ++++
 
 The `geo_shape` data type facilitates the indexing of and searching
-with arbitrary geoshapes such as rectangles and polygons. It should be
-used when either the data being indexed or the queries being executed
-contain shapes other than just points.
+with arbitrary geoshapes such as rectangles, lines and polygons. If the data being
+indexed contains shapes other than just points, it is necessary to use this mapping.
+If the data contains only points, it can be indexed as either
+<<geo-point,`geo_point`>> or `geo_shape`.
 
-You can query documents using this type using
-a <<query-dsl-geo-shape-query,`geo_shape` query>>.
+Documents using this type can be used:
+
+* to find geoshapes within:
+** a <<query-dsl-geo-bounding-box-query,bounding box>>
+** a certain <<query-dsl-geo-distance-query,distance>> of a central point
+** a <<query-dsl-geo-shape-query,`geo_shape` query>> (for example, intersecting polygons).
+* to aggregate documents by geographic grids:
+** either <<search-aggregations-bucket-geohashgrid-aggregation,`geo_hash`>>
+** or <<search-aggregations-bucket-geotilegrid-aggregation,`geo_tile`>>.
+
+Grid aggregations over `geo_hex` grids are not supported for `geo_shape` fields.
 
 [[geo-shape-mapping-options]]
 [discrete]
 ==== Mapping Options
 
-The `geo_shape` mapping maps GeoJSON geometry objects to the `geo_shape`
+The `geo_shape` mapping maps GeoJSON or WKT geometry objects to the `geo_shape`
 type. To enable it, users must explicitly map fields to the `geo_shape`
 type.
 
@@ -258,7 +268,7 @@ POST /example/_doc
 
 A polygon's orientation indicates the order of its vertices: `RIGHT`
 (counterclockwise) or `LEFT` (clockwise). {es} uses a polygon’s orientation to
-determine if it crosses the international dateline (+/-180° longitude). 
+determine if it crosses the international dateline (+/-180° longitude).
 
 You can set a default orientation for WKT polygons using the
 <<geo-shape-mapping-options,`orientation` mapping parameter>>. This is because

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

@@ -4,16 +4,14 @@
 <titleabbrev>Geoshape</titleabbrev>
 ++++
 
-Filter documents indexed using the `geo_shape` or `geo_point` type.
+Filter documents indexed using either the <<geo-shape,`geo_shape`>> or the
+<<geo-point,`geo_point`>> type.
 
-Requires the <<geo-shape,`geo_shape` mapping>> or the
-<<geo-point,`geo_point` mapping>>.
-
-The `geo_shape` query uses the same grid square representation as the
-`geo_shape` mapping to find documents that have a shape that is related
-to the query shape, using a specified spatial relationship: either intersects,
+The `geo_shape` query uses the same <<geoshape-indexing-approach, index>> as
+the `geo_shape` or `geo_point` mapping to find documents that have a shape that
+is related to the query shape, using a specified
+<<geo-shape-spatial-relations, spatial relationship>>: either intersects,
 contained, within or disjoint.
-It will also use the same Prefix Tree configuration as defined for the field mapping.
 
 The query supports two ways of defining the query shape, either by
 providing a whole shape definition, or by referencing the name of a shape
@@ -229,6 +227,7 @@ GET /example/_search
 --------------------------------------------------
 
 
+[[geo-shape-spatial-relations]]
 ==== Spatial relations
 
 The following is a complete list of spatial relation operators available when