Update file_picker_writable, note reason for private fork

See hpoul/file_picker_writable#20

Author: amake

pubspec.lock

@@ -134,10 +134,10 @@ packages:
     description:
       path: "."
       ref: directory-picker
-      resolved-ref: b2a1135514b4759faea15393ebd6bac367b59f5e
+      resolved-ref: de0d3e23a486eb58f1747ca5be0acc5129215189
       url: "https://github.com/amake/file_picker_writable.git"
     source: git
-    version: "2.0.3"
+    version: "2.1.0+1"
   flutter:
     dependency: "direct main"
     description: flutter

pubspec.yaml

@@ -14,9 +14,11 @@ dependencies:
   dynamic_fonts: ^2.2.0
   # dynamic_fonts:
   #   path: ../dynamic-fonts-flutter
-  # file_picker_writable: ^2.0.0
+  # file_picker_writable: ^2.1.0
   file_picker_writable:
-  #   path: ../file_picker_writable
+    # path: ../file_picker_writable
+    # Using private fork pending merge of
+    # https://github.com/hpoul/file_picker_writable/pull/20
     git:
       url: https://github.com/amake/file_picker_writable.git
       ref: directory-picker