[DOCS] Reformat classic token filter docs (#48314)

docs/reference/analysis/tokenfilters/classic-tokenfilter.asciidoc

@@ -1,9 +1,147 @@
 [[analysis-classic-tokenfilter]]
-=== Classic Token Filter
+=== Classic token filter
+++++
+<titleabbrev>Classic</titleabbrev>
+++++
 
-The `classic` token filter does optional post-processing of
-terms that are generated by the <<analysis-classic-tokenizer,`classic` tokenizer>>.
+Performs optional post-processing of terms generated by the
+<<analysis-classic-tokenizer,`classic` tokenizer>>.
 
-This filter removes the english possessive from the end of words, and
-it removes dots from acronyms.
+This filter removes the english possessive (`'s`) from the end of words and
+removes dots from acronyms. It uses Lucene's
+https://lucene.apache.org/core/{lucene_version_path}/analyzers-common/org/apache/lucene/analysis/standard/ClassicFilter.html[ClassicFilter].
+
+[[analysis-classic-tokenfilter-analyze-ex]]
+==== Example
+
+The following <<indices-analyze,analyze API>> request demonstrates how the
+classic token filter works.
+
+[source,console]
+--------------------------------------------------
+GET /_analyze
+{
+  "tokenizer" : "classic",
+  "filter" : ["classic"],
+  "text" : "The 2 Q.U.I.C.K. Brown-Foxes jumped over the lazy dog's bone."
+}
+--------------------------------------------------
+
+The filter produces the following tokens:
+
+[source,text]
+--------------------------------------------------
+[ The, 2, QUICK, Brown, Foxes, jumped, over, the, lazy, dog, bone ]
+--------------------------------------------------
+
+/////////////////////
+[source,console-result]
+--------------------------------------------------
+{
+  "tokens" : [
+    {
+      "token" : "The",
+      "start_offset" : 0,
+      "end_offset" : 3,
+      "type" : "<ALPHANUM>",
+      "position" : 0
+    },
+    {
+      "token" : "2",
+      "start_offset" : 4,
+      "end_offset" : 5,
+      "type" : "<ALPHANUM>",
+      "position" : 1
+    },
+    {
+      "token" : "QUICK",
+      "start_offset" : 6,
+      "end_offset" : 16,
+      "type" : "<ACRONYM>",
+      "position" : 2
+    },
+    {
+      "token" : "Brown",
+      "start_offset" : 17,
+      "end_offset" : 22,
+      "type" : "<ALPHANUM>",
+      "position" : 3
+    },
+    {
+      "token" : "Foxes",
+      "start_offset" : 23,
+      "end_offset" : 28,
+      "type" : "<ALPHANUM>",
+      "position" : 4
+    },
+    {
+      "token" : "jumped",
+      "start_offset" : 29,
+      "end_offset" : 35,
+      "type" : "<ALPHANUM>",
+      "position" : 5
+    },
+    {
+      "token" : "over",
+      "start_offset" : 36,
+      "end_offset" : 40,
+      "type" : "<ALPHANUM>",
+      "position" : 6
+    },
+    {
+      "token" : "the",
+      "start_offset" : 41,
+      "end_offset" : 44,
+      "type" : "<ALPHANUM>",
+      "position" : 7
+    },
+    {
+      "token" : "lazy",
+      "start_offset" : 45,
+      "end_offset" : 49,
+      "type" : "<ALPHANUM>",
+      "position" : 8
+    },
+    {
+      "token" : "dog",
+      "start_offset" : 50,
+      "end_offset" : 55,
+      "type" : "<APOSTROPHE>",
+      "position" : 9
+    },
+    {
+      "token" : "bone",
+      "start_offset" : 56,
+      "end_offset" : 60,
+      "type" : "<ALPHANUM>",
+      "position" : 10
+    }
+  ]
+}
+--------------------------------------------------
+/////////////////////
+
+[[analysis-classic-tokenfilter-analyzer-ex]]
+==== Add to an analyzer
+
+The following <<indices-create-index,create index API>> request uses the
+classic token filter to configure a new 
+<<analysis-custom-analyzer,custom analyzer>>.
+
+[source,console]
+--------------------------------------------------
+PUT /classic_example
+{
+    "settings" : {
+        "analysis" : {
+            "analyzer" : {
+                "classic_analyzer" : {
+                    "tokenizer" : "classic",
+                    "filter" : ["classic"]
+                }
+            }
+        }
+    }
+}
+--------------------------------------------------