Use the diff code highlighting tag.
```diff
- foo
+ bar
Example:
-function () {
+function greet() {
console.log('Hello world');
}- bad
+ good- boring
+ awesomeIntertesting
- meh
+ woot-this is kind of cool
+this is awesome!!!!!-light
+dark-war
+peace-mean.js
+sean.js-Hello
+Good day!- Foo
+ Bar- War
+ Peas- Let's see
+ That sounds great- Hate
+ Love- foo
+ bar+ foo
+ bar- old skool
+ reactive programming- boom
+ whoa-foo
+bar- foo
+ bar- Callbacks
+ Observables- words
+ facts- old
+ new- old
+ new- meh
+ woot