Add ability to configure background position utilities

Author: benface

defaultConfig.stub.js

@@ -367,6 +367,33 @@ module.exports = {
   backgroundColors: colors,
 
 
+  /*
+  |-----------------------------------------------------------------------------
+  | Background positions      https://tailwindcss.com/docs/background-positions
+  |-----------------------------------------------------------------------------
+  |
+  | Here is where you define your background positions. We provide some 
+  | common values that are useful in most projects, but feel free to add 
+  | other positions that are specific to your project here as well.
+  |
+  | Class name: .bg-{position}
+  | CSS property: background-position
+  |
+  */
+
+  backgroundPosition: {
+    'bottom': 'bottom',
+    'center': 'center',
+    'left': 'left',
+    'left-bottom': 'left bottom',
+    'left-top': 'left top',
+    'right': 'right',
+    'right-bottom': 'right bottom',
+    'right-top': 'right top',
+    'top': 'top',
+  },
+
+
   /*
   |-----------------------------------------------------------------------------
   | Background sizes               https://tailwindcss.com/docs/background-size

src/generators/backgroundPosition.js

@@ -1,15 +1,10 @@
-import defineClasses from '../util/defineClasses'
+import _ from 'lodash'
+import defineClass from '../util/defineClass'
 
-export default function() {
-  return defineClasses({
-    'bg-bottom': { 'background-position': 'bottom' },
-    'bg-center': { 'background-position': 'center' },
-    'bg-left': { 'background-position': 'left' },
-    'bg-left-bottom': { 'background-position': 'left bottom' },
-    'bg-left-top': { 'background-position': 'left top' },
-    'bg-right': { 'background-position': 'right' },
-    'bg-right-bottom': { 'background-position': 'right bottom' },
-    'bg-right-top': { 'background-position': 'right top' },
-    'bg-top': { 'background-position': 'top' },
+export default function({ backgroundPosition }) {
+  return _.map(backgroundPosition, (position, className) => {
+    return defineClass(`bg-${className}`, {
+      'background-position': position,
+    })
   })
 }