Apply tags to example posts

Signed-off-by: SeongJae Park <sj38.park@gmail.com>

exampleSite/content/post/2015-02-20-test-markdown.md

@@ -2,6 +2,7 @@
 title: Test markdown
 subtitle: Each post also has a subtitle
 date: 2015-02-20
+tags: ["example", "markdown"]
 ---
 
 You can write regular [markdown](http://markdowntutorial.com/) here and Jekyll will automatically convert it to a nice webpage.  I strongly encourage you to [take 5 minutes to learn how to write in markdown](http://markdowntutorial.com/) - it'll teach you how to transform regular text into bold/italics/headings/tables/etc.
@@ -49,4 +50,4 @@ var foo = function(x) {
   return(x + 5);
 }
 foo(3)
-{{</ highlight >}}
+{{</ highlight >}}

exampleSite/content/post/2016-03-08-code-sample.md

@@ -2,6 +2,7 @@
 title: Code Sample
 subtitle: Using Pygments or Highlight.js
 date: 2016-03-08
+tags: ["example", "code"]
 ---
 
 The following are two code samples using syntax highlighting.
@@ -27,4 +28,4 @@ The following is a code sample using triple backticks ( ``` ) code fencing provi
     num2 = prompt("Enter second number")
     sum = parseInt(num1) + parseInt(num2) // "+" means "add"
     alert("Sum = " + sum)  // "+" means combine into a string
-```
+```