feat(all): adds Catalan flag

src/flags/countries/_index.scss

@@ -69,4 +69,7 @@ $flag-height: calc($flag-size / 3) * 2;
   @import "v";
   @import "y";
   @import "z";
+
+  // Flags by region name
+  @import "regions/c";
 }

src/flags/countries/regions/c.scss

@@ -0,0 +1 @@
+@import "catalonia";

src/flags/countries/regions/catalonia.scss

@@ -0,0 +1,12 @@
+// Catalonia
+&-cat {
+  position: relative;
+  background-image:
+    repeating-linear-gradient(
+      to bottom,
+      #fcdd09,
+      #fcdd09 calc(40px / 9),
+      #da121a calc(40px / 9),
+      #da121a calc(40px / 9 * 2)
+    );
+}