Modify default build config

- Modified the  build config of `electron-builder` provided in thie boilerplate
to build universal mac apps (for apple silicon & intel CPU), and 32 & 64 bit
Windows exe by defualt.

Author: iamWing

package.json

@@ -13,8 +13,8 @@
     "next-patch": "npm --no-git-tag-version version prepatch",
     "next-minor": "npm --no-git-tag-version version preminor",
     "next-major": "npm --no-git-tag-version version premajor",
-    "build:win": "electron-builder build --win --x64",
-    "build:mac": "electron-builder build --mac --x64"
+    "build:win": "electron-builder build --win",
+    "build:mac": "electron-builder build --mac"
   },
   "build": {
     "appId": "com.devtography.electron_boilerplate",
@@ -24,11 +24,19 @@
       "output": "./out/"
     },
     "mac": {
-      "target": "dmg"
+      "target": {
+        "target": "dmg",
+        "arch": "universal"
+      }
     },
     "win": {
-      "target": "nsis",
-      "asar": true
+      "target": {
+        "target": "nsis",
+        "arch": [
+          "x64",
+          "ia32"
+        ]
+      }
     },
     "nsis": {
       "oneClick": false,