Doc: Refine geoip filter example (#18101) (#18104)

Added sample output structure for geoip filter
(cherry picked from commit 86ee4df)

Co-authored-by: Karen Metts <[email protected]>
Co-authored-by: kaisecheng <[email protected]>

Author: 3 people

docs/static/transforming-data.asciidoc

@@ -433,19 +433,28 @@ The <<plugins-filters-geoip,geoip filter>> adds geographical information about t
 filter {
   geoip {
     source => "clientip"
+    target => "[source]"
   }
 }
 --------------------------------------------------------------------------------
 +
-After the geoip filter is applied, the event will be enriched with geoip fields.
+After the geoip filter is applied, the event is enriched with geoip fields.
 For example:
 +
 [source,json]
 --------------------------------------------------------------------------------
-filter {
-  geoip {
-    source => "clientip"
-  }
+"source" => {
+  "geo" => {
+    "country_name" => "France",
+    "country_iso_code" => "FR",
+    "continent_code" => "EU",
+    "location" => {
+      "lon" => 2.3387,
+      "lat" => 48.8582
+    },
+    "timezone" => "Europe/Paris"
+  },
+  "ip" => "82.67.74.30"
 }
 --------------------------------------------------------------------------------