Add 'Soundfiles access' section.

README.md

@@ -57,6 +57,14 @@ In the display zone, zoom can be changed with *2 fingers up/down slide* on macOS
 #### SVG Diagrams
 The _Diagram_ tab allows displaying the circuit SVG diagram. You can navigate inside it by clicking on the dark blue part to go down in the circuit hierarchy, or clicking on the diagram border to go up in the circuit hierarchy.
 
+#### Soundfiles access
+
+The [soundfile](https://faustdoc.grame.fr/manual/syntax/#soundfile-primitive) primitive can be used in the IDE, **in ScriptProcessor only for now**. The audio files have to be accessed:
+
+- either using a full URL like https://raw.githubusercontent.com/grame-cncm/GameLAN/master/baliphone/Gamelan_1_1_C_gauche.flac
+
+- or by defining the soundfile base URL folder with the `declare soundfiles "https://raw.githubusercontent.com/grame-cncm/GameLAN/master/baliphone";` metadata, then the actual audio file namle in the code. See this [example](https://github.com/grame-cncm/GameLAN/blob/master/baliphone/Baliphone.dsp). Several base URL can be listed with `declare soundfiles "https://url1;"https://url2;"https://url3" kind of syntax.
+
 ## Recommended Browsers
 The recommended browsers are the latest versions of Chrome and Firefox for AudioWorklet and MIDI, but it requires an https connection to use the audio inputs.