every markdown list item should be `1.` !

Using `1.` for every item in a Markdown ordered list (instead of incrementing numbers) keeps Git diffs clean and preserves `git blame` history. Since Markdown only uses the first number to set the starting value of the rendered HTML ordered list, all subsequent items can safely be `1.` without affecting rendering. Inserting or removing list items won't cause unnecessary line changes across the whole list.