Added AlpConvAtlas Description

Author: sdellachiesa

_data/gallery.yml

@@ -1,6 +1,6 @@
 - title: AlpConv Atlas
   subtitle: Alpine Convention Atlas 
-  description: The Alpine Convention Atlas is the place where you can discover and browse the relevant data and information concerning the Alps! Its aim is to collect, organize and disseminate the results of research activities carried out by the Alpine Convention and its Working Groups as well as by European projects in the Alpine region.
+  description: The Alpine Convention Atlas is the repository where you can discover and browse the Alps' relevant data and information. It aims to collect, organize and disseminate the results of research activities carried out by the Alpine Convention and its Working Groups.
   url: https://www.atlas.alpconv.org/
   image: AlpConvAtlas.jpg