fix: Add a button-controlled pause and resume example

COMMITMSG

@@ -0,0 +1,7 @@
+fix: Add a button-controlled pause and resume example
+
+- examples/ButtonPauseResume/ButtonPauseResume.ino
+
+Fixes #4
+
+Signed-off-by: Vedant Madane <6527493+VedantMadane@users.noreply.github.com>

examples/ButtonPauseResume/ButtonPauseResume.ino

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+/*
+  Button-controlled pause and resume example.
+  Wire a button from BUTTON_PIN to GND (INPUT_PULLUP).
+  Opens serial and toggles a paused flag on press.
+*/
+const int BUTTON_PIN = 2;
+bool paused = false;
+bool lastStable = HIGH;
+unsigned long lastDebounceMs = 0;
+
+void setup() {
+  pinMode(BUTTON_PIN, INPUT_PULLUP);
+  Serial.begin(115200);
+  Serial.println("Button pause/resume example");
+}
+
+void loop() {
+  int reading = digitalRead(BUTTON_PIN);
+  if (reading != lastStable && (millis() - lastDebounceMs) > 30) {
+    lastDebounceMs = millis();
+    lastStable = reading;
+    if (reading == LOW) {
+      paused = !paused;
+      Serial.println(paused ? "PAUSED" : "RESUMED");
+    }
+  }
+  if (!paused) {
+    // do work while running
+    delay(10);
+  }
+}