[DOCS] Update documentation for `max_token_length`

In 1.4 the behavior is different due to
https://issues.apache.org/jira/browse/LUCENE-5897

docs/reference/analysis/analyzers/standard-analyzer.asciidoc

@@ -20,7 +20,7 @@ type:
 |`stopwords` |A list of stopwords to initialize the stop filter with.
 Defaults to an 'empty' stopword list Check
 <<analysis-stop-analyzer,Stop Analyzer>> for more details.
-|`max_token_length` |The maximum token length. If a token is seen that
-exceeds this length then it is discarded. Defaults to `255`.
+|`max_token_length` |The maximum token length. If a token is seen that exceeds
+this length then it is split at `max_token_length` intervals. Defaults to `255`.
 |=======================================================================