[FEATURE] Add Stylelint and Standard for testing

.stylelintrc

@@ -0,0 +1,26 @@
+{
+  "extends": [
+    "stylelint-config-standard"
+  ],
+  "plugins": [
+    "stylelint-use-logical"
+  ],
+  "rules": {
+    "color-hex-length": "long",
+    "color-hex-case": "upper",
+    "max-empty-lines": 3,
+    "number-leading-zero": "always",
+    "no-descending-specificity": null,
+    "shorthand-property-no-redundant-values": [true, {"severity": "warning"}],
+    "declaration-no-important": true,
+    "no-duplicate-at-import-rules": true,
+    "selector-max-id": 0,
+    "declaration-block-no-duplicate-properties": true,
+    "rule-empty-line-before": ["always-multi-line", {"ignore": ["after-comment"]}],
+    "value-keyword-case": "lower",
+    "string-quotes": "single",
+    "selector-class-pattern": ["^([a-z][a-z0-9]*)(-[a-z0-9]+)*(_[a-z0-9]+)*(__[a-z]((_|-)?[a-z0-9])*)?(--[a-z0-9]((_|-)?[a-z0-9\\\\\\/])*)?$", { "resolveNestedSelectors": true }],
+    "csstools/use-logical": true,
+    "declaration-block-no-redundant-longhand-properties": null
+  }
+}