Add in occasional message to ask for support

bin/todo_marker

@@ -4,6 +4,10 @@
 # !/usr/bin/env ruby
 
 require 'todo_marker'
+require 'date'
+
+DONATION_LINK = 'https://www.paypal.com/donate/?hosted_button_id=YF5XS7ZXQ6F8A'
+TIMESTAMP_FILE = File.join(Dir.home, '.todo_marker_last_donation_prompt')
 
 if ARGV.empty?
   puts 'Usage: todo_marker <directory>'
@@ -18,3 +22,22 @@ end
 
 TodoMarker.generate_todo_md(directory)
 puts "TODO.md has been generated in the #{directory} directory."
+
+def should_show_donation_message?
+  return true unless File.exist?(TIMESTAMP_FILE)
+
+  last_prompt = Date.parse(File.read(TIMESTAMP_FILE).strip)
+  (Date.today - last_prompt).to_i >= 7 # Show message once a week
+rescue ArgumentError
+  true
+end
+
+def update_timestamp
+  File.write(TIMESTAMP_FILE, Date.today.to_s)
+end
+
+if should_show_donation_message?
+  puts "\nEnjoying TodoMarker? Consider donating to support development:"
+  puts DONATION_LINK
+  update_timestamp
+end