obs: background removal plugin added

wiki/obs.md

@@ -3,13 +3,18 @@
 [Open Broadcaster Software](https://obsproject.com) - short OBS - is a free
 and open source software for video recording and live streaming.
 
-## Virtual Camera
+## Plugins
 
-By using virtual camera the views of OBS can be used as an additional camera
+There are several plugins made by non-obs developers.
+The plugins introduce different and new features.
+
+### Virtual Camera
+
+By using a virtual camera the views of OBS can be used as an additional camera
 output, making it possible to add effects and more to the video feed of the
 camera.
 
-### Installation (Linux)
+#### Installation (Linux)
 
 First of all [V4L2](./linux/v4l2.md) needs to be set up.
 This guide assumes it is set up according to the section in the
@@ -19,3 +24,17 @@ Additionally `obs-v4l2sink` needs to be installed.
 Under `Tools/v4l2sink` select the device path set up in V4L2 and the `YUV420`
 video format.
 Afterwards the virtual camera can be started.
+
+### Background Removal
+
+Background removal removes the background of a camera image stream.
+The removed background can be replaced with color key filters.
+
+#### Installation
+
+Made by royshil
+[the github page](https://github.com/royshil/obs-backgroundremoval#linux)
+describes various possibilities to install the background removal for OBS on
+different systems.
+On Linux systems background removal is often contained in a package named
+`obs-backgroundremoval` or similarly.