Updated stylelint config

Author: michaelx

.stylelintrc

@@ -3,6 +3,7 @@
     "stylelint-order"
   ],
   "rules": {
+    "at-rule-semicolon-space-before": "never",
     "block-no-empty": true,
     "block-opening-brace-newline-after": "always-multi-line",
     "block-opening-brace-space-after": "always-single-line",
@@ -23,6 +24,7 @@
     "declaration-colon-space-before": "never",
     "declaration-no-important": true,
     "font-family-name-quotes": "always-where-recommended",
+    "font-family-no-missing-generic-family-keyword": true,
     "function-calc-no-unspaced-operator": true,
     "indentation": 2,
     "length-zero-no-unit": true,
@@ -33,11 +35,11 @@
     "media-feature-name-no-vendor-prefix": true,
     "media-feature-range-operator-space-after": "always",
     "media-feature-range-operator-space-before": "always",
+    "no-duplicate-at-import-rules": true,
     "no-eol-whitespace": true,
     "no-extra-semicolons": true,
     "no-invalid-double-slash-comments": true,
     "no-unknown-animations": true,
-    #"no-unsupported-browser-features": true, Can be occasionally enabled to debug. Checks code against "Can I use" database.
     "number-leading-zero": "never",
     "order/properties-order": [
       "content",