Add nullish coalescing to multiple articles, refactor operators, renumber the chapter

1-js/02-first-steps/14-switch/1-rewrite-switch-if-else/task.md

@@ -0,0 +1,26 @@
+importance: 5
+
+---
+
+# Rewrite the "switch" into an "if"
+
+Write the code using `if..else` which would correspond to the following `switch`:
+
+```js
+switch (browser) {
+  case 'Edge':
+    alert( "You've got the Edge!" );
+    break;
+
+  case 'Chrome':
+  case 'Firefox':
+  case 'Safari':
+  case 'Opera':
+    alert( 'Okay we support these browsers too' );
+    break;
+
+  default:
+    alert( 'We hope that this page looks ok!' );
+}
+```
+