added *.css rules in .editorconfig for indent consistency

.editorconfig

@@ -9,5 +9,8 @@ trim_trailing_whitespace = true
 [*.js]
 max_line_length = 100
 
+[*.css]
+indent_size = 4
+
 [*.md]
 trim_trailing_whitespace = false

addons/fullscreen/fullscreen.css

@@ -7,4 +7,4 @@
     width: auto;
     height: auto;
     z-index: 255;
-}
+}

demo/style.css

@@ -23,4 +23,4 @@ h1 {
 
 #terminal-container .terminal .terminal-cursor {
     background-color: #fafafa;
-}
+}