firefox-addon - Purpose of doc/main.md in firefox addon?

Question

After creating a new addon skeleton there is nothing in doc/main.md,
and the addon sdk documentation does not outline specific format of data to save in this file.
What is the purpose of it?
Should it contain specific data related to each .js file?
Or completely up to the developer to decide format and/or content?

rob@workLaptop:~/test$ cfx init
* lib directory created
* data directory created
* test directory created
* doc directory created
* README.md written
* generated jID automatically: jid1-hDoBEUyOVCBwuw
* package.json written
* test/test-main.js written
* lib/main.js written
* doc/main.md written

Your sample add-on is now ready.
Do "cfx test" to test it and "cfx run" to try it.  Have fun!
rob@workLaptop:~/test$ ls
data  doc  lib  package.json  README.md  test
rob@workLaptop:~/test$ cat doc/main.md 
rob@workLaptop:~/test$

Answer 1

拡張子「.md」は、Markdown ファイルを指します。

これらは通常、アドオンの機能の概要を示すために使用されます。

構文/形式は、ここで stackoverflow で使用されているものと似ています。このMarkdown Cheatsheetで、書き方のリファレンスを確認できます。

hereやhereのように、アドオンの main.md の例をいくつか見ることもできます。