Bump Stylelint to 14 (#795)

Author: aaronshekey

.stylelintrc

@@ -1,6 +1,13 @@
 {
-  "extends": "stylelint-config-standard",
+  "extends": "stylelint-config-recommended-less",
+  "customSyntax": "postcss-less",
+  "plugins": [
+    "stylelint-less"
+  ],
   "rules": {
+    "at-rule-no-unknown": null,
+    "less/color-no-invalid-hex": null,
+    "less/no-duplicate-variables": null,
     "indentation": 4,
     "max-empty-lines": 2,
     "no-invalid-double-slash-comments": null,

lib/css/atomic/_stacks-flex.less

@@ -101,7 +101,7 @@
         //
         //  ----------------------------------------------------------------------------
         .flex-fixed-item-spacing(@spacing, @num, @count: 1) when (@count =< @num) {
-            @item-width: (@count * 100% / @num);
+            @itemWidth: (@count * 100% / @num);
 
             > .flex--item@{count} {
                 margin: (@spacing / 2);
@@ -121,7 +121,7 @@
             &.flex__allitems@{count} > .d-flex,                     // [2]
             &.flex__allcells@{count} > .flex--item,                 // [2]
             &.flex__allitems@{count} > .flex--item {                // [2]
-                flex-basis: calc(~"@{item-width} - @{spacing}");
+                flex-basis: calc(~"@{itemWidth} - @{spacing}");
             }
 
             #stacks-internals #flex-builder-helpers .flex-fixed-item-spacing(@spacing, @num, (@count + 1));

lib/css/components/_stacks-badges.less

@@ -167,6 +167,7 @@
         margin-top: 0;
     }
 }
+
 .s-badge__staff {
     // Staff badges are always "Stack Overflow Orange"
     .badge-styles(var(--orange-300), var(--orange-100), var(--orange-900));

lib/css/components/_stacks-progress-bars.less

@@ -37,7 +37,6 @@
     background-color: var(--green-400);
 }
 
-
 //  $$   LABEL
 //       For when there's descriptive, label copy within the progress bar
 //  ----------------------------------------------------------------------------
@@ -53,7 +52,6 @@
     z-index: @zi-base + 2;
 }
 
-
 //  ===========================================================================
 //  $   VARIATION PROGRESS BACKGROUNDS
 //  ---------------------------------------------------------------------------
@@ -78,7 +76,6 @@
     }
 }
 
-
 //  ===========================================================================
 //  $   BADGE PROGRESS BARS
 //  ===========================================================================
@@ -95,7 +92,6 @@
     background-color: transparent;
 }
 
-
 //  $$  GOLD
 //  ---------------------------------------------------------------------------
 .s-progress__gold {