Update article.md

Author: leviding

2-ui/5-loading/02-script-async-defer/article.md

@@ -37,7 +37,7 @@ Luckily, there are two `<script>` attributes that solve the problem for us: `def
 
 ## defer
 
-The `defer` attribute tells the browser not to wait for the script. Instead, the browser will continue to process the HTML, build DOM. The script loads "in the background", and then runs when the DOM is fully built. 
+The `defer` attribute tells the browser not to wait for the script. Instead, the browser will continue to process the HTML, build DOM. The script loads "in the background", and then runs when the DOM is fully built.
 
 Here's the same example as above, but with `defer`:
 
@@ -97,13 +97,13 @@ The `async` attribute is somewhat like `defer`. It also makes the script non-blo
 
 The `async` attribute means that a script is completely independent:
 
-- The browser doesn't block on `async` scripts (like `defer`). 
-- Other scripts don't wait for `async` scripts, and `async` scripts don't wait for them. 
+- The browser doesn't block on `async` scripts (like `defer`).
+- Other scripts don't wait for `async` scripts, and `async` scripts don't wait for them.
 - `DOMContentLoaded` and async scripts don't wait for each other:
     - `DOMContentLoaded` may happen both before an async script (if an async script finishes loading after the page is complete)
     - ...or after an async script (if an async script is short or was in HTTP-cache)
 
-In other words, `async` scripts load in the background and run when ready. The DOM and other scripts don't wait for them, and they don't wait for anything. A fully independent script that runs when loaded. As simple, at it can get, right? 
+In other words, `async` scripts load in the background and run when ready. The DOM and other scripts don't wait for them, and they don't wait for anything. A fully independent script that runs when loaded. As simple, at it can get, right?
 
 Here's an example similar to what we've seen with `defer`: two scripts `long.js` and `small.js`, but now with `async` instead of `defer`.