Migrate docs from the other repo

docs/reference/js/lessons/blink/activity.md

@@ -0,0 +1,55 @@
+# blink activity
+
+Turn an LED on and off with forever 
+
+### ~avatar avatar
+
+### @video td/videos/blink-0
+
+Let's learn how to blink an LED.
+
+### ~
+
+Have you ever tried to blink a flashlight at night? The concept is fairly simply: turn on the light, wait for a little, turn off the light, wait again, and repeat. That's exactly what we need to code to get a blinking LED.
+
+Let's start by adding a line of code that turns on the LED at position ``2, 2``.
+
+```
+led.plot(2, 2) 
+```
+
+Run your script to make sure it's correct. Then, let's add code to **pause** `500` milliseconds and turn off the LED.
+
+```
+led.plot(2, 2)
+basic.pause(500) 
+led.unplot(2, 2) 
+```
+
+We've got the LED blinking once. Let's add another pause and turn on the LED again.
+
+```
+led.plot(2, 2)
+basic.pause(500)
+led.unplot(2, 2)
+basic.pause(500) 
+led.plot(2, 2) 
+```
+
+The current code works but it only blinks once! We are going to use a `basic->forever` loop and move the code inside it to repeat it forever. We've dropped the second `led-plot` line since we don't need it in the loop.
+
+```
+basic.forever(() => {
+    led.plot(2, 2)
+    basic.pause(500)
+    led.unplot(2, 2)
+    basic.pause(500)
+})
+```
+
+### ~avatar boothing
+
+Excellent, you're ready to continue with the [challenges](/microbit/lessons/blink/challenges)!
+
+### ~
+