Add anchor link for responsive vs adaptive design question (#133)

* added responsive design vs adaptive design qn

Added link to the list of qns above

* correct typo

added s

Author: jenlky

questions/css-questions.md

@@ -30,6 +30,7 @@ Answers to [Front-end Job Interview Questions - CSS Questions](https://github.co
 * [What existing CSS frameworks have you used locally, or in production? How would you change/improve them?](#what-existing-css-frameworks-have-you-used-locally-or-in-production-how-would-you-changeimprove-them)
 * [Have you played around with the new CSS Flexbox or Grid specs?](#have-you-played-around-with-the-new-css-flexbox-or-grid-specs)
 * [Can you explain the difference between coding a web site to be responsive versus using a mobile-first strategy?](#can-you-explain-the-difference-between-coding-a-web-site-to-be-responsive-versus-using-a-mobile-first-strategy)
+* [How is responsive design different from adaptive design?](#how-is-responsive-design-different-from-adaptive-design)
 * [Have you ever worked with retina graphics? If so, when and what techniques did you use?](#have-you-ever-worked-with-retina-graphics-if-so-when-and-what-techniques-did-you-use)
 * [Is there any reason you'd want to use `translate()` instead of `absolute` positioning, or vice-versa? And why?](#is-there-any-reason-youd-want-to-use-translate-instead-of-absolute-positioning-or-vice-versa-and-why)