Quicker is an adjective, used to describe nouns. You could say "design quicker websites", "quicker" in that case describing an aspect of the website. If you wanted to describe the manner in which you will do the designing, you have to use the adverb "quickly"-- "design websites quickly". Adding the adverb "more" to modify the adverb "quickly" is the proper way to make it comparative.
* "...More Quickly".
Quicker is an adjective, used to describe nouns. You could say "design quicker websites", "quicker" in that case describing an aspect of the website. If you wanted to describe the manner in which you will do the designing, you have to use the adverb "quickly"-- "design websites quickly". Adding the adverb "more" to modify the adverb "quickly" is the proper way to make it comparative.