Adding help link to Add extension box and making the box wider

(cherry picked from commit 575390b306b99c604fe63be9a37cd76a109846e8)

Source commit: 23c03f49bcdcb32ab5d72f7d606a4340186bffde

source/forms/Preferences.cpp

@@ -2626,7 +2626,7 @@ void __fastcall TPreferencesDialog::AddExtension()
   std::unique_ptr<TStrings> History(CloneStrings(CustomWinConfiguration->History[HistoryKey]));
   UnicodeString Path;
   if (InputDialog(LoadStr(ADD_EXTENSION_CAPTION), LoadStr(ADD_EXTENSION_PROMPT), Path,
-        HELP_NONE, History.get(), true) &&
+        HELP_ADD_EXTENSION, History.get(), true, NULL, true, 400) &&
       !Path.IsEmpty())
   {
     CustomWinConfiguration->History[HistoryKey] = History.get();

source/resource/HelpWin.h

@@ -68,5 +68,6 @@
 #define HELP_SITE_RAW                "ui_login_raw"
 #define HELP_PUTTY_SETTINGS          "ui_login_environment#putty"
 #define HELP_CLOSE_SESSION_WORKSPACE "workspace"
+#define HELP_ADD_EXTENSION           "ui_pref_commands#extensions"
 
 #endif // TextsWin