fix for pixel letterSpacing

Author: lukasoppermann

dist/plugin.js

@@ -120,7 +120,7 @@ const extractFonts: extractorInterface = (tokenNodes: TextStyle[], prefixArray:
       },
       letterSpacing: {
         value: roundWithDecimals(node.letterSpacing.value),
-        unit: <NumericUnitTypes>node.letterSpacing.unit.toLowerCase(),
+        unit: <NumericUnitTypes>(node.letterSpacing.unit.toLowerCase() === 'pixels' ? 'pixel' : node.letterSpacing.unit.toLowerCase()),
         type: 'number' as PropertyType
       },
       lineHeight: {

dist/ui.html

@@ -4,6 +4,7 @@ import { StandardTokenInterface, StandardTokenTypes, StandardTokenDataInterface,
 import roundWithDecimals from '../utilities/roundWithDecimals'
 import { tokenExtensions } from './tokenExtensions'
 import config from '@config/config'
+import { UnitTypePixel } from '@typings/valueTypes'
 
 const lineHeightToDimension = (values): number => {
   if (values.lineHeight.unit === 'pixel') {