Update docs.html

Author: nicolas-raoul

docs.html

@@ -31,6 +31,10 @@
     </nav>
 
     <div class="container text-left my-3" id="docs">
+        <h2 id="language-fallback"><a href="#language-fallback">Why am I seeing foreign languages?</a></h2>
+        <p>When a label, caption or description is not available in your language, the app falls back to another language. We consider it is better than showing nothing. For instance, a person whose phone is in Hindi might be happy to see English descriptions of items for which a Hindi description is not available.</p>
+        <p>Of course, you are more than welcome to contribute labels and descriptions in your language. To do so, please tap the Wikidata barcode icon in Nearby, or "View file page", or "View item page". This will open the website where translations can be contributed. Thanks a lot!</p>
+
         <h2 id="geotagging"><a href="#geotagging">Geotagging (adding location data to pictures)</a></h2>
         <p>Pictures with geolocation data are much more valuable, so please:</p>
         <ol>