Add headphones icon

CHANGELOG.md

@@ -27,6 +27,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
   - `feather`
   - `filter`
   - `hash`
+  - `headphones`
   - `home`
   - `info`
   - `instagram`

icons-manifest.json

@@ -52,6 +52,7 @@
   "bell",
   "bell-off",
   "music",
+  "headphones",
   "star",
   "award",
   "cloud",

icons/headphones.svg

+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="#000" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <path d="M3,18V12a9,9,0,0,1,18,0v6"/>
+  <path d="M21,19a2,2,0,0,1-2,2H18a2,2,0,0,1-2-2V16a2,2,0,0,1,2-2h3Z"/>
+  <path d="M3,19a2,2,0,0,0,2,2H6a2,2,0,0,0,2-2V16a2,2,0,0,0-2-2H3Z"/>
+</svg>
\ No newline at end of file