DOC-2761 limitations section, fixes and note in geo data type page

Author: andy-stark-redis

content/develop/data-types/geospatial.md

@@ -20,6 +20,14 @@ weight: 80
 Redis geospatial indexes let you store coordinates and search for them.
 This data structure is useful for finding nearby points within a given radius or bounding box.
 
+{{< note >}}Take care not to confuse the Geospatial data type with the
+[Geospatial]({{< relref "/develop/interact/search-and-query/advanced-concepts/geo" >}})
+features in [Redis Query Engine]({{< relref "/develop/interact/search-and-query" >}}).
+Although there are some similarities between these two features, the data type is intended
+for simpler use cases and doesn't have the range of format options and queries
+available in Redis Query Engine.
+{{< /note >}}
+
 ## Basic commands
 
 * [`GEOADD`]({{< relref "/commands/geoadd" >}}) adds a location to a given geospatial index (note that longitude comes before latitude with this command).

content/develop/interact/search-and-query/advanced-concepts/geo.md

@@ -190,3 +190,13 @@ See
 for more information about these query types and see
 [Geospatial indexing]({{< relref "/develop/interact/search-and-query/indexing/geoindex" >}})
 for examples of indexing `GEOSHAPE` fields.
+
+## Limitations of geographical coordinates
+
+Planet Earth is actually shaped more like an
+[ellipsoid](https://en.wikipedia.org/wiki/Earth_ellipsoid) than a perfect sphere.
+The spherical coordinate system used by Redis Query Engine is a close
+approximation to the shape of the Earth but not exact. For most practical
+uses of geospatial queries, the approximation works very well, but you
+shouldn't rely on it if you need very precise location data (for example, to track
+the GPS locations of boats in an emergency response system).

content/develop/interact/search-and-query/indexing/geoindex.md

@@ -9,8 +9,8 @@ categories:
 - oss
 - kubernetes
 - clients
-description: How to index and search geospatial data
-linkTitle: Geo indexing
+description: Options for indexing geospatial data
+linkTitle: Geospatial
 title: Geospatial indexing
 weight: 3
 ---
@@ -32,9 +32,8 @@ reference page for a full description of both types.
 
 ## `GEO`
 
-The following [`redis-cli`]({{< relref "/develop/tools/cli" >}}) command
-creates a `GEO` index for JSON objects that contain the geospatial data
-in a field called `location`:
+The following command creates a `GEO` index for JSON objects that contain
+the geospatial data in a field called `location`:
 
 ```bash
 > FT.CREATE productidx ON JSON PREFIX 1 product: SCHEMA $.location AS location GEO