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

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

@@ -0,0 +1,20 @@
+To precisely match the functionality of `switch`, the `if` must use a strict comparison `'==='`.
+
+For given strings though, a simple `'=='` works too.
+
+```js no-beautify
+if(browser == 'Edge') {
+  alert("You've got the Edge!");
+} else if (browser == 'Chrome'
+ || browser == 'Firefox'
+ || browser == 'Safari'
+ || browser == 'Opera') {
+  alert( 'Okay we support these browsers too' );
+} else {
+  alert( 'We hope that this page looks ok!' );
+}
+```
+
+Please note: the construct `browser == 'Chrome' || browser == 'Firefox' …` is split into multiple lines for better readability.
+
+But the `switch` construct is still cleaner and more descriptive.