Add Fullscreen in viewer, Track links with Google Analytics, Use .env file

- Fullscreen is a component that watches a store value set by the Carousel component on a picture click
- Use a .env file for API and website related settings and informations
- Google Analytics is now in place, tracking each routes link and viewer photo change

src/organisms/Carousel.svelte

@@ -1,7 +1,7 @@
 <script>
     import { onMount, createEventDispatcher } from 'svelte'
     import { stores } from '@sapper/app'
-    import { currentLocation } from '../utils/store'
+    import { currentLocation, fullscreen } from '../utils/store'
     import { getThumbnail, formatDate } from '../utils/functions'
     const dispatch = createEventDispatcher()
     const { page } = stores()
@@ -50,6 +50,8 @@
 
         // Dispatch current photo
         sendCurrentPhoto()
+        // Reset fullscreen value if open
+        fullscreen.set()
     }
 
     // Send current photo to event
@@ -145,6 +147,7 @@
                     class:gallery__photo--prev={photo === prevPhoto}
                     class:gallery__photo--active={photo === currentPhoto}
                     class:gallery__photo--next={photo === nextPhoto}
+                    on:click={event => viewer && fullscreen.set(currentPhoto)}
                 >
                     <source media="(min-width: 968px)" srcset={getThumbnail(photo.image.private_hash, 1400)}>
                     <source media="(min-width: 800px)" srcset={getThumbnail(photo.image.private_hash, 900)}>