rtimer: Writing a Timer with Aider

Aider + Claude Sonnet 3.5 This morning, I needed a timer to spend only 10 minutes reading a book. I searched for CLI tools but couldn't find anything immediately that suited my needs due to laziness. So, I decided to write one myself with the help of AI. Using Aider coupled with Claude Sonnet 3.5, I was able to get something working on the first try. Afterward, I added a few features: