Update geospatial stage description for the GEOADD command and its usage.

Author: rohitpaulk

stage_descriptions/geospatial-01-zt4.md

@@ -1,32 +1,43 @@
 In this stage, you'll add support for responding to the `GEOADD` command.
 
 ### The `GEOADD` command
-The `GEOADD` command adds a location (with longitude, latitude, and name) to a key. It stores the location as a [sorted set](https://redis.io/docs/latest/develop/data-types/sorted-sets/) under the specified key. If the key doesn’t exist, a new sorted set is created under the specified name and the location is inserted to it. If the key exists, the location is inserted in the sorted set.
+
+The [`GEOADD` command](https://redis.io/docs/latest/commands/geoadd/) adds a location (with longitude, latitude, and name) to a key. It stores the location as a [sorted set](https://redis.io/docs/latest/develop/data-types/sorted-sets/) under the specified key.
 
 Example usage:
 
 ```bash
 > GEOADD places -0.0884948 51.506479 "London"
 (integer) 1
 ```
-The argument order of `GEOADD` argument – key, longitude, latitude, member (longitude first, then latitude).
+
+The arguments `GEOADD` accepts are:
+
+1. `key`: The key to store the location in.
+2. `longitude`: The longitude of the location.
+3. `latitude`: The latitude of the location.
+4. `member`: The name of the location.
 
 It returns the count of elements added, encoded as a RESP Integer.
 
+In this stage, you'll only implement the response to the `GEOADD` command. We'll get to validating arguments and storing locations in later stages.
+
 ### Tests
+
 The tester will execute your program like this:
 
 ```bash
 $ ./your_program.sh
 ```
 
-It will then send a `GEOADD` command specifying a key, latitude, longitude, and location name.
+It will then send a `GEOADD` command:
 
 ```bash
 $ redis-cli GEOADD places 11.5030378 48.164271 Munich
 ```
 
-The tester will expect the response to be `:1\r\n`, which is 1(number of locations added) encoded as a RESP integer.
+The tester will expect the response to be `:1\r\n`, which is 1 (number of locations added) encoded as a RESP integer.
 
 ### Notes
-- In this stage, you will only implement responding the the `GEOADD` command. You don't need to store the locations yet. We'll get to storing the locations in the later stages.
+
+- In this stage, you only need to implement responding to the `GEOADD` command. We'll get to validating arguments and storing locations in later stages.