Update README.md

[sButtons](https://github.com/sButtons/sbuttons) repository is now archived and not accepting new PRs. This was the only repo under the CSS category so I am removing it.

README.md

@@ -14,7 +14,6 @@ If you are not a programmer but would like to contribute, check out the [Awesome
 - [C++](#c-2)
 - [Clojure](#clojure)
 - [ClojureScript](#clojurescript)
-- [CSS](#css)
 - [Dart](#dart)
 - [Elixir](#elixir)
 - [Go](#go)
@@ -74,10 +73,6 @@ If you are not a programmer but would like to contribute, check out the [Awesome
 
 - [LightTable](https://github.com/LightTable/LightTable) _(label: good-first-issue)_ <br> The Next Generation code editor! One of the top funded projects on KickStarter.
 
-## CSS
-
-- [sButtons](https://github.com/shahednasser/sbuttons) _(label: good-first-issue)_ <br> Simple buttons you can easily use for your next project.
-
 ## Dart
 
 - [dart.dev](https://github.com/dart-lang/site-www) _(label: beginner)_ <br> A website covering Dart language and common libraries, for developers of Dart libraries, web apps, server-side code, and mobile (Flutter) apps.

data.json

@@ -175,15 +175,6 @@
             ],
             "description": "The Next Generation code editor! One of the top funded projects on KickStarter."
         },
-        {
-            "name": "sButtons",
-            "link": "https://github.com/shahednasser/sbuttons",
-            "label": "good-first-issue",
-            "technologies": [
-                "CSS"
-            ],
-            "description": "Simple buttons you can easily use for your next project."
-        },
         {
             "name": "dart.dev",
             "link": "https://github.com/dart-lang/site-www",