add mobygratis as free instrumental music resource

Author: fharper

resources/misc.md

@@ -11,6 +11,7 @@ Some resources to help on different levels
 - [Fake Data Generators](#fake-data-generators)
 - [Fonts](#fonts)
 - [Licenses](#licenses)
+- [Music](#music)
 - [People Management](#people-management)
 - [Pictures & Images](#pictures--images)
 - [Social Media](#social-media)
@@ -85,6 +86,10 @@ Some resources to help on different levels
 
 - [Unsplash](https://unsplash.com/license)
 
+## Music
+
+- [mobygratis](https://mobygratis.com): free instrumental music
+
 ## People Management
 
 - [Awesome List of resources on leading people and being a manager](https://github.com/LappleApple/awesome-leading-and-managing)