Update readme

Readme.md

@@ -60,6 +60,22 @@ int main(int argc, char **argv) {
 }
 ```
 
+## Compiling
+
+If you're on macOS, just use the Xcode project file to build all dependencies,
+you will need to have `libao` installed via Homebrew.
+
+If you're on a Unix/Linux you can use the provided `Makefile`s. This will create
+one static library per dependency and one for the audio library in the sub-dir
+`audio/.build` and it`s subdirs.
+
+So currently you will get:
+- `libaudio-test`: the test binary created from `AudioLib/main.c`
+- `audio/.build/libaudio.a`: static library for the audio library
+- `audio/.build/libmad/libmad.a`: MP3 decoder library (dependency, GPL license)
+- `audio/.build/speexdsp/libspeexresampler.a`: Speex resampler library (dependency, MIT license)
+
+
 ## Implemented elements
 
 Currently not a lot of elements are implemented, but these here are: