renamed text from bulgarian to english

Author: AlexDimov-04

Single page application - Aria web-page/index.html

@@ -189,7 +189,7 @@ <h1 class="heading">songs</h1>
     <!-- gallery section -->
 
     <section class="gallery" id="gallery">
-        <h1 class="heading">снимки от участия</h1>
+        <h1 class="heading">images from concerts</h1>
 
         <ul class="controls" role="list">
             <li class="button active" data-filter="all">всички</li>