Fix typo in strings-and-runes (#414)

examples/strings-and-runes/strings-and-runes.go

@@ -17,7 +17,7 @@ import (
 func main() {
 
 	// `s` is a `string` assigned a literal value
-	// representing the world "hello" in the Thai
+	// representing the word "hello" in the Thai
 	// language. Go string literals are UTF-8
 	// encoded text.
 	const s = "สวัสดี"

public/strings-and-runes

@@ -82,7 +82,7 @@ introduction to the topic.</p>
         <tr>
           <td class="docs">
             <p><code>s</code> is a <code>string</code> assigned a literal value
-representing the world &ldquo;hello&rdquo; in the Thai
+representing the word &ldquo;hello&rdquo; in the Thai
 language. Go string literals are UTF-8
 encoded text.</p>