Make a document-based application

Add the basic necessities for a document-based application. This is what
I came up with on 2023-09-10. The `DocumentWindowController` was just an
initial idea and doesn't do anything: we create the required window
controller in `Document`.

The `CFBundleDocumentTypes` entry enables us to interact with text
files.

This confirms that the "Open Recent" menu does get added automatically
below the "Open" menu.

1 files changed, 14 insertions, 0 deletions

diff --git a/Info.plist b/Info.plist
index e1b9e8c..6a6eedd 100644
--- a/Info.plist
+++ b/Info.plist
@@ -24,5 +24,19 @@
 	<string>10.12</string>
 	<key>NSHumanReadableCopyright</key>
 	<string>Copyright © 2023 Teddy Wing</string>
+
+	<key>CFBundleDocumentTypes</key>
+	<array>
+		<dict>
+			<key>CFBundleTypeRole</key>
+			<string>Editor</string>
+			<key>LSItemContentTypes</key>
+			<array>
+				<string>public.plain-text</string>
+			</array>
+			<key>NSDocumentClass</key>
+			<string>Document</string>
+		</dict>
+	</array>
 </dict>
 </plist>