Mention FreeBSD as supported system

Closes #131

README.md

@@ -3,7 +3,7 @@
 *Cardinal, the Rack!*
 
 A virtual Eurorack modular synthesizer platform,
-available as JACK standalone and LV2, VST2 and VST3 audio plugin for Linux, macOS and Windows.
+available as JACK standalone and LV2, VST2 and VST3 audio plugin for FreeBSD, Linux, macOS and Windows.
 
 This is a [DPF-based](https://github.com/DISTRHO/DPF/) plugin wrapper around [VCV Rack](https://github.com/VCVRack/Rack/),
 using its code directly instead of forking the project.  

doc/DIFFERENCES.md

@@ -27,6 +27,7 @@ Bellow follows a list of features comparing the official plugin to Cardinal.
 | Plugin inside itself           | No, will crash            | Yes                             | Technical limitations prevent Rack Pro from loading inside itself |
 | Multi-threaded engine          | Yes                       | No, uses host audio thread      | Intentional in Cardinal, for removing jitter |
 | Supports ARM systems           | No                        | Yes                             | This means Apple M1 too, yes |
+| Supports BSD systems           | No                        | Yes                             | Available as FreeBSD port |
 | Synth plugin variant           | 16 ins, 16 outs           | 2 ins, 2 outs                   | |
 | FX plugin variant              | 16 ins, 16 outs           | 2 ins, 2 outs                   | |
 | Raw-CV plugin variant          | Unsupported               | 8 audio IO + 10 CV IO           | Available in JACK, LV2 and VST3 formats, not possible in VST2 |