added some web worker documentation

SQUASHED: AUTO-COMMIT-demos-worker-index.md,AUTO-COMMIT-demos-worker-sum-client.js,AUTO-COMMIT-demos-worker-sum.js,AUTO-COMMIT-demos-worker-sum-systemjs-client.js,AUTO-COMMIT-demos-worker-sum-systemjs-worker.js,AUTO-COMMIT-demos-worker-sum-worker.js,AUTO-COMMIT-doc-figures-worker.drawio,

demos/worker/index.md

@@ -0,0 +1,47 @@
+# Web Worker in Lively4
+
+Worker, worker, worker... and which one is the real worker?
+
+Problem: There are too many modules in  Lively4 that have "worker" in the name, can we change this? Are they all needed? How do they work together?
+
+<script>
+  // setup
+  async function fileEditor(fileName) {
+    let editor = await (<lively-editor></lively-editor>)
+    editor.setURL(lively4url + fileName)
+    editor.loadFile()
+    return editor
+  }
+  ""
+</script>
+
+## Classic Webworker
+
+
+### Client Code
+
+
+<script>fileEditor("/demos/worker/sum-client.js")</script>
+
+### Worker
+
+<script>fileEditor("/demos/worker/sum-worker.js")</script>
+
+## SystemJS Worker
+
+Since we are not in Kansas any more... we have no lively or systemjs on the worker side (yet). 
+
+### Client code
+
+
+<script>fileEditor("/demos/worker/sum-systemjs-client.js")</script>
+
+### Worker
+
+<script>fileEditor("/demos/worker/sum-systemjs-worker.js")</script>
+
+
+## Hide onmessage and postMessage 
+
+In <edit://src/babylonian-programming-editor/worker/babylonian-manager.js> and it's worker <edit://src/babylonian-programming-editor/worker/babylonian-worker.js>, the actual webworker is hidden with a promised method call...
+

demos/worker/sum-client.js

@@ -0,0 +1,8 @@
+
+var myworker = new Worker(lively4url + "/demos/worker/sum-worker.js")
+
+myworker.onmessage = function(evt) {
+  lively.notify("sum = " + evt.data)
+}
+
+myworker.postMessage([3, 4]);

demos/worker/sum-systemjs-client.js

@@ -0,0 +1,9 @@
+import SystemjsWorker from "src/worker/systemjs-worker.js"
+
+var myworker = new SystemjsWorker(lively4url + "/demos/worker/sum-systemjs-worker.js")
+
+myworker.onmessage = function(evt) {
+  lively.notify("sum = " + evt.data)
+}
+
+myworker.postMessage([3, 4]);

demos/worker/sum-systemjs-worker.js

@@ -0,0 +1,5 @@
+import {sum} from "./sum.js"
+
+export function onmessage(e) {
+  postMessage(sum(e.data));
+}

demos/worker/sum-worker.js

@@ -0,0 +1,9 @@
+
+onmessage = function(e) {
+  var array = e.data
+  var sum = 0
+  for(let ea of array) {
+    sum += ea
+  }
+  postMessage(sum);
+}

demos/worker/sum.js

@@ -0,0 +1,8 @@
+
+export function sum(array) {
+  var sum = 0
+  for(let ea of array) {
+    sum += ea
+  }
+  return sum
+}