replace ishMinMax with ishViewportRange

part of https://github.com/pattern-lab/styleguidekit-assets-default/releases/tag/v3.5.0

i know this file isnt really used

Author: bmuenzenmeyer

patternlab-config.json

@@ -47,8 +47,11 @@
     "tools-all": false,
     "tools-docs": false
   },
-  "ishMinimum": "240",
-  "ishMaximum": "2600",
+  "ishViewportRange": {
+    "s": [240, 500],
+    "m": [500, 800],
+    "l": [800, 2600]
+  },
   "patternStateCascade": ["inprogress", "inreview", "complete"],
   "patternExportPatternPartials": [],
   "patternExportDirectory": "./pattern_exports/",