Merge pull request #25 from collective/petschki-patch-1

add `collective.behavior.relatedmedia`

README.md

@@ -143,6 +143,7 @@ _Add-ons that handle image, video and audio content._
 
 * [collective.autoscaling](https://github.com/collective/collective.autoscaling) - Automatic scaling of large images. Useful to reduce your database size when editors upload too large images.
 * [collective.behavior.banner](https://github.com/collective/collective.behavior.banner) - A behavior to create banners and sliders from banners.
+* [collective.behavior.relatedmedia](https://github.com/collective/collective.behavior.relatedmedia) - A behavior to create/upload/manage media relations (Image, File) for content types.
 * [collective.lazysizes](https://github.com/collective/collective.lazysizes) - Integration of lazysizes, a lightweight lazy loader, into Plone.
 * [collective.wavesurfer](https://github.com/collective/collective.wavesurfer) - Implementation of https://wavesurfer-js.org audio player for Plone.
 * [plone.app.imagecropping](https://github.com/collective/plone.app.imagecropping) - Crops Images in Plone manually using cropper JS library.