Mention VST3 in readme

Signed-off-by: falkTX <falktx@falktx.com>

Author: falkTX

README.md

@@ -3,7 +3,7 @@
 Studio quality, open-source reverb. Its release was intended to provide a practical demonstration of Dattorro’s figure-of-eight reverb structure and provide the open source community with a high quality reverb.
 
 This is a DPF'ied build of [MVerb](https://github.com/martineastwood/mverb/), allowing a proper Linux version with UI.<br/>
-LADSPA, DSSI, LV2 and VST plugin versions can be built, plus a JACK-Standalone.
+LADSPA, DSSI, LV2, VST2 and VST3 plugin versions can be built, plus a JACK-Standalone.
 
 ## Screenshot
 ![MVerb](https://raw.githubusercontent.com/DISTRHO/MVerb/master/plugins/MVerb/Screenshot.png "MVerb")<br/>