add new rules (#3)

Author: malrase

.sass-lint.yml

@@ -50,9 +50,9 @@ rules:
         - smaller-than-laptop-breakpoint
         - on-load
   nesting-depth:
-      - 1
-      -
-        max-depth: 5
+    - 1
+    -
+      max-depth: 5
   no-css-comments: 2
   no-debug: 1
   no-duplicate-properties: 1
@@ -62,5 +62,10 @@ rules:
   no-invalid-hex: 2
   no-mergeable-selectors: 1
   no-warn: 1
+  quotes:
+    - 2
+    -
+      style: double
   single-line-per-selector: 2
   space-after-colon: 2
+  zero-unit: 2