Fix Advanced Search Syntax documentation

changelogs/unreleased-ee/4175-fix-elasticsearch-syntax-docs.yml

+---
+title: Fix Advanced Search Syntax documentation
+merge_request: 3571
+author:
+type: fixed

doc/user/search/advanced_search_syntax.md

@@ -23,13 +23,13 @@ you need the search results to be as efficient as possible. You have a feeling
 of what you want to find (e.g., a function name), but at the same you're also
 not so sure.
 
-In that case, using the regular expressions in your query will yield much better
-results.
+In that case, using the advanced search syntax in your query will yield much
+better results.
 
 ## Using the Advanced Syntax Search
 
-The Advanced Syntax Search supports queries of ranges, wildcards, regular
-expressions, fuzziness and much more.
+The Advanced Syntax Search supports fuzzy or exact search queries with prefixes,
+boolean operators, and much more.
 
 Full details can be found in the [Elasticsearch documentation][elastic], but
 here's a quick guide:
@@ -42,7 +42,6 @@ here's a quick guide:
 * To group terms together, use parentheses: `bug | (display +sound)`
 * To match a partial word, use `*`: `bug find_by_*`
 * To find a term containing one of these symbols, use `\`: `argument \-last`
-* To limit the results based on the time  "created_at:[2012-01-01 TO 2012-12-31]" and other sweet stuff
 
 [ee]: https://about.gitlab.com/gitlab-ee/
 [elastic]: https://www.elastic.co/guide/en/elasticsearch/reference/5.3/query-dsl-simple-query-string-query.html#_simple_query_string_syntax