Support Markdown jot files

[matt-dray]

Close #85.

• Accepted .txt and .md file paths.
• Added a test for Markdown files.
• Noted text file types in README.

Can you give it a try @Lextuga007 and let me know if it works?

[Lextuga007]

I installed from branch 85-md and changed the existing jot file to another name but when I did a jot I didn't get a prompt for the type of file. Just jot.txt was set up. Even creating a jot.md doesn't get jot to update the md as it creates a new txt.

[matt-dray]

Aha, cheers, this is because jot looks in the config.json file to find the JOT_PATH value. If the file at that path is missing, jot creates it (probably not ideal, so I've added #87).

A better test of this might be to delete/rename your existing config.json file. Then running jot will prompt for a new text file path, which will be recorded into the new config.json. Like this (on macOS):

$ jot hello
📝 Provide a path for the jot file (.txt or .md): ~/Desktop/jot.md
✅ Set JOT_PATH to /Users/mattdray/Desktop/jot.md
✅ Jotted at 2026-06-19 18:19
$ cat ~/Desktop/jot.md
[2026-06-19 18:19] hello