Migrate docs from the other repo

docs/reference/basic/forever.md

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+# Forever
+
+Repeat code [in the background](/microbit/reference/control/in-background) forever.
+
+```sig
+basic.forever(() => {
+})
+```
+
+### Example: compass
+
+The following example constantly checks the [compass heading](/microbit/reference/input/compass-heading) and updates the screen with the direction.
+
+```blocks
+basic.forever(() => {
+    let heading = input.compassHeading()
+    if (heading < 45) {
+        basic.showString("N", 100)
+    } else if (heading < 135) {
+        basic.showString("E", 100)
+    }
+    else if (heading < 225) {
+        basic.showString("S", 100)
+    }
+    else {
+        basic.showString("W", 100)
+    }
+})
+```
+
+### Example: counter
+
+The following example continually shows the current value of a global variable:
+
+```blocks
+let num = 0
+basic.forever(() => {
+    basic.showNumber(num, 150)
+})
+input.onButtonPressed("A", () => {
+    num = num + 1
+})
+```
+
+### Contention for the LED display
+
+If you have multiple processes that each show something on the LED screen, you may get unexpected results. Try, for example:
+
+```blocks
+basic.forever(() => {
+    basic.showNumber(6789, 150)
+})
+input.onButtonPressed(Button.A, () => {
+    basic.showNumber(2, 150)
+})
+```
+
+### Lessons
+
+[blink](/microbit/lessons/blink), [bounce-image](/microbit/lessons/bounce-image),  [snowflake-fall](/microbit/lessons/snowflake-fall), [flashing-heart](/microbit/lessons/flashing-heart)
+
+### See also
+
+[while](/microbit/js/while), [on button pressed](/microbit/reference/input/on-button-pressed), [in background](/microbit/reference/control/in-background)
+