Devicetree updates (#481)

* **New Features**
  * Added I2S audio support (i2s0) for LilyGO TLora Pager, M5Stack Cardputer (standard & Adv), M5Stack Core2, M5Stack CoreS3, and Guition JC1060P; moved i2s0 entry in LilyGO TDeck.

* **Chores**
  * Device-tree grammar now separately recognizes and ignores line (//) and block (/* */) comments.
  * Added reference docs to severa DTS files

* **Documentation**
  * Reworked ideas/roadmap

Devices/m5stack-core2/m5stack,core2.dts

@@ -3,7 +3,9 @@
 #include <tactility/bindings/root.h>
 #include <tactility/bindings/esp32_gpio.h>
 #include <tactility/bindings/esp32_i2c.h>
+#include <tactility/bindings/esp32_i2s.h>
 
+// Reference: https://docs.m5stack.com/en/core/Core2
 / {
 	compatible = "root";
 	model = "M5Stack Core2";
@@ -32,4 +34,16 @@
 		pin-sda-pullup;
 		pin-scl-pullup;
 	};
+
+	// NS4168: Speaker and microphone
+	// TODO: Init microphone via I2C: https://github.com/m5stack/M5Unified/blob/a6256725481f1bc366655fa48cf03b6095e30ad1/src/M5Unified.cpp#L391C19-L391C44
+	i2s0 {
+		compatible = "espressif,esp32-i2s";
+		port = <I2S_NUM_0>;
+		pin-bclk = <12>;
+		pin-ws = <0>;
+		pin-data-out = <2>;
+		pin-data-in = <34>;
+		pin-mclk = <GPIO_PIN_NONE>;
+	};
 };