Add doc link to custom rules syntax help.

Fixes https://gitlab.com/kicad/code/kicad/issues/13727

common/dialogs/html_message_box.cpp

@@ -25,8 +25,10 @@
 #include <wx/clipbrd.h>
 #include <wx/log.h>
 #include <wx/textctrl.h>
+#include <wx/uri.h>
 #include <string_utils.h>
 #include <dialogs/html_message_box.h>
+#include <build_version.h>
 
 
 HTML_MESSAGE_BOX::HTML_MESSAGE_BOX( wxWindow* aParent, const wxString& aTitle,
@@ -144,6 +146,20 @@ void HTML_MESSAGE_BOX::ShowModeless()
 }
 
 
+void HTML_MESSAGE_BOX::OnHTMLLinkClicked( wxHtmlLinkEvent& event )
+{
+    wxString href = event.GetLinkInfo().GetHref();
+
+    if( href.StartsWith( wxS( "https://docs.kicad.org/" ) ) )
+    {
+        href.Replace( wxS( "GetMajorMinorVersion" ), GetMajorMinorVersion() );
+
+        wxURI uri( href );
+        wxLaunchDefaultBrowser( uri.BuildURI() );
+    }
+}
+
+
 void HTML_MESSAGE_BOX::OnCharHook( wxKeyEvent& aEvent )
 {
     // shift-return (Mac default) or Ctrl-Return (GTK) for OK

include/dialogs/html_message_box.h

@@ -83,6 +83,9 @@ public:
      */
     void ShowModeless();
 
+    void OnHTMLLinkClicked( wxHtmlLinkEvent& event ) override;
+
+
 protected:
     void reload();
 

pcbnew/dialogs/panel_setup_rules_help.md

@@ -311,4 +311,8 @@ Deprecated; use `intersectsArea()` instead.
     (rule high-current
         (constraint track_width (min 1.0mm))
         (constraint connection_width (min 0.8mm))
-        (condition "A.NetClass == 'Power'"))
+        (condition "A.NetClass == 'Power'"))
+
+### Documentation
+
+For the full documentation see [https://docs.kicad.org](https://docs.kicad.org/GetMajorMinorVersion/pcbnew/#custom_design_rules).

pcbnew/dialogs/panel_setup_rules_help_md.h

@@ -312,4 +312,8 @@ _HKI( "### Top-level Clauses\n"
 "    (rule high-current\n"
 "        (constraint track_width (min 1.0mm))\n"
 "        (constraint connection_width (min 0.8mm))\n"
-"        (condition \"A.NetClass == 'Power'\"))" );
+"        (condition \"A.NetClass == 'Power'\"))\n"
+"\n"
+"### Documentation\n"
+"\n"
+"For the full documentation see [https://docs.kicad.org](https://docs.kicad.org/GetMajorMinorVersion/pcbnew/#custom_design_rules)." );