add new sounds collection (CC0 1.0)

options.html

@@ -115,22 +115,34 @@
                   <p class="label">Mentions</p>
                   <select name="" id="sndMention" class="sndOpt container">
                     <option value="false">none</option>
+                    <optgroup label="twister">
                       <option value="1">beat</option>
                       <option value="2">pip</option>
                       <option value="3">vibro</option>
                       <option value="4">flip</option>
                       <option value="5">click</option>
+                    <optgroup>
+                    <optgroup label="freesound.org">
+                      <option value="freesound.org/569127">569127</option>
+                      <option value="freesound.org/485837">485837</option>
+                    <optgroup>
                   </select>
                 </div>
                 <div>
                   <p class="label">Direct Messages</p>
                   <select name="" id="sndDM" class="sndOpt container">
                     <option value="false">none</option>
+                    <optgroup label="twister">
                       <option value="1">beat</option>
                       <option value="2">pip</option>
                       <option value="3">vibro</option>
                       <option value="4">flip</option>
                       <option value="5">click</option>
+                    <optgroup>
+                    <optgroup label="freesound.org">
+                      <option value="freesound.org/569127">569127</option>
+                      <option value="freesound.org/485837">485837</option>
+                    <optgroup>
                   </select>
                 </div>
                 <div>

sound/freesound.org/README.md

@@ -0,0 +1,11 @@
+All samples in this directory are from http://freesound.org and have been  
+placed in the public domain via the Creative Commons 0 License:  
+
+http://creativecommons.org/publicdomain/zero/1.0/  
+
+Original files was converted using ffmpeg software (libmp3lame/libvorbis)  
+
+Links to original samples:  
+
+* `569127` - https://freesound.org/people/josefpres/sounds/569127  
+* `485837` - https://freesound.org/people/univ_lyon3/sounds/485837