firmware wip - add favico to HTMLheader

Arduino/CanGrow/CanGrow.ino

@@ -184,13 +184,13 @@ const char HTMLheaderP1[] PROGMEM = R"EOF(
 <title>
 )EOF";
  // here comes the page title in returnHTMLheader()
- 
+
 // second part of HTML header stuff
+// Having the whole CSS here ensures it's all the time present
 const char HTMLheaderP2[] PROGMEM = R"EOF(
  </title>
- <!-- <link rel='stylesheet' href='/style.css'> -->
-  <style>
-  /* Having the whole CSS here ensures it's all the time present*/
+ <link rel="icon" href="data:;base64,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">
+ <style>
 body {
   color: #cae0d0;
   background-color: #1d211e;