Clean up project warnings (#199)

* Set "recommended project settings" for Mac app

* Add default fallback for font typingAttribute

* Clean up linter errors

* Update extension iconset

* Fix spm errors and upgrade sparkle (#203)

* Switch WriteFreely package import from ssh to https

* Sign macOS project target for Development

This fixes a crash-on-launch bug when running Product > Run from Xcode (Product > Archive should work correctly). See sparkle-project/Sparkle#2056 for more details.

Bug introduced by commit:
671b054

* Update Sparkle to v2.0 from official repo

Previously, we forked the repo to the WriteFreely org because Sparkle didn't support tag-based SPM updates. We therefore had to pull from the `master` branch, so forking insulated us from unexpected changes.

As of 2.x Sparkle now allows for tag-based updating via SPM; we'll allow patch updates but stop short of 2.1 until we can vet changes.

* Add MacUpdatesViewModel ObservableObject

* Use MacUpdatesViewModel to handle Sparkle update logic

Author: AngeloStavrow

ActionExtension-iOS/Media.xcassets/AppIconExtension.appiconset/AppIconExtension@2x.png

@@ -1,93 +1,109 @@
 {
   "images" : [
     {
+      "filename" : "notification-icon@2x.png",
       "idiom" : "iphone",
       "scale" : "2x",
       "size" : "20x20"
     },
     {
+      "filename" : "notification-icon@3x.png",
       "idiom" : "iphone",
       "scale" : "3x",
       "size" : "20x20"
     },
     {
+      "filename" : "icon-small@2x.png",
       "idiom" : "iphone",
       "scale" : "2x",
       "size" : "29x29"
     },
     {
+      "filename" : "icon-small@3x.png",
       "idiom" : "iphone",
       "scale" : "3x",
       "size" : "29x29"
     },
     {
+      "filename" : "icon-40@2x.png",
       "idiom" : "iphone",
       "scale" : "2x",
       "size" : "40x40"
     },
     {
+      "filename" : "icon-40@3x.png",
       "idiom" : "iphone",
       "scale" : "3x",
       "size" : "40x40"
     },
     {
-      "filename" : "AppIconExtension@2x.png",
+      "filename" : "icon-60@2x.png",
       "idiom" : "iphone",
       "scale" : "2x",
       "size" : "60x60"
     },
     {
-      "filename" : "AppIconExtension@3x.png",
+      "filename" : "icon-60@3x.png",
       "idiom" : "iphone",
       "scale" : "3x",
       "size" : "60x60"
     },
     {
+      "filename" : "notification-icon~ipad.png",
       "idiom" : "ipad",
       "scale" : "1x",
       "size" : "20x20"
     },
     {
+      "filename" : "notification-icon~ipad@2x.png",
       "idiom" : "ipad",
       "scale" : "2x",
       "size" : "20x20"
     },
     {
+      "filename" : "icon-small.png",
       "idiom" : "ipad",
       "scale" : "1x",
       "size" : "29x29"
     },
     {
+      "filename" : "icon-small@2x-1.png",
       "idiom" : "ipad",
       "scale" : "2x",
       "size" : "29x29"
     },
     {
+      "filename" : "icon-40.png",
       "idiom" : "ipad",
       "scale" : "1x",
       "size" : "40x40"
     },
     {
+      "filename" : "icon-40@2x-1.png",
       "idiom" : "ipad",
       "scale" : "2x",
       "size" : "40x40"
     },
     {
+      "filename" : "icon-76.png",
       "idiom" : "ipad",
       "scale" : "1x",
       "size" : "76x76"
     },
     {
+      "filename" : "icon-76@2x.png",
       "idiom" : "ipad",
       "scale" : "2x",
       "size" : "76x76"
     },
     {
+      "filename" : "icon-83.5@2x.png",
       "idiom" : "ipad",
       "scale" : "2x",
       "size" : "83.5x83.5"
     },
     {
+      "filename" : "ios-marketing.png",
       "idiom" : "ios-marketing",
       "scale" : "1x",
       "size" : "1024x1024"