[help] convert search_syntax.rst to help page

searx/help/en/search-syntax.md

@@ -0,0 +1,31 @@
+# Search syntax
+
+SearXNG allows you to modify the default categories, engines and search language
+via the search query.
+
+Prefix `!` to set Category/engine.
+
+Prefix: `:` to set the language.
+
+Abbrevations of the engines and languages are also accepted.  Engine/category
+modifiers are chainable and inclusive (e.g. with [!it !ddg !wp
+qwer]($search?q=!it+!ddg+!wp+qwer)) search in IT category **and** duckduckgo
+**and** wikipedia for ``qwer``).
+
+See the [preferences]($preferences) for the list of engines,
+categories and languages.
+
+## Examples
+
+Search in wikipedia for `qwer`:
+
+* [!wp qwer]($search?q=!wp+qwer)
+* [!wikipedia qwer]($search?q=!wikipedia+qwer)
+
+Image search:
+
+* [!images Cthulu]($search?q=!images+Cthulu)
+
+Custom language in wikipedia:
+
+* [:hu !wp hackerspace]($search?q=:hu+!wp+hackerspace)

searx/user_help.py

@@ -18,7 +18,10 @@ class HelpPage(NamedTuple):
 
 
 # Whenever a new .md file is added to help/ it needs to be added here
-_TOC = ('about',)
+_TOC = (
+    'about',
+    'search-syntax',
+)
 
 PAGES: Dict[str, HelpPage] = {}
 """ Maps a filename under help/ without the file extension to the rendered page. """
@@ -49,6 +52,7 @@ def render(app: flask.Flask):
         variables['index'] = url_for('index')
         variables['preferences'] = url_for('preferences')
         variables['stats'] = url_for('stats')
+        variables['search'] = url_for('search')
 
     for pagename in _TOC:
         filename = 'help/en/' + pagename + '.md'