[search] Add German synonym

Signed-off-by: x7z4w <x7z4w@noreply.codeberg.org>

libs/indexer/search_string_utils.cpp

@@ -33,7 +33,8 @@ std::array<UniString, 11> const kAllowedMisprints = {
 };
 
 static std::pair<UniString, UniString> const kPreprocessReplacements[] = {
-    {MakeUniString("a. d."), MakeUniString("an den")},
+    {MakeUniString("a. d."), MakeUniString("auf an den der")},
+    {MakeUniString("a.d."), MakeUniString("auf an den der")}, // hacks to handle "(auf/an) (den/der)" in German
     {MakeUniString("arm. gen"), MakeUniString("armádneho generála")},
     {MakeUniString("atr'"), MakeUniString("ambohitr'")},
     {MakeUniString("a. v."), MakeUniString("asociación vecinal")},

libs/search/query_params.cpp

@@ -94,7 +94,6 @@ unordered_map<string, vector<string>> const kSynonyms = {
     {"accs", {"access"}},
     {"aceq", {"acequia"}},
     {"ach", {"ancien chemin"}},
-    //{"a.d", {"auf der", "an der"}}, // unreachable
     {"adi", {"ambodi"}},
     {"adm", {"admirała", "admirał"}},
     {"afb", {"air force base"}},