City, Country About IDs in Post Markdown Files
The IDs in post markdown (.md) files is just for ordering. The site orders the files by descensing by their filename, this way if you want to move a post up or down you can easily do so by changing the ID.
About URLs and IDs
Post URLs come from the slug defined above markdown front matter. Changing the ID won't change the post link, but
it will only change the ordering on the homepage.
New posts
By default you can increment the biggest post ID by 1 and use it for your new post. This way, latest post will be at the top.
Be careful about string ordering
Be careful that this is not a numeric ordering, 11 will come before 2. Because we are ordering descending, 2 will come to top. If you want to use numeric ordering, you can use 02, 11, 12, etc. This way, 02 will come before 11.
When you have posts with IDs 1, 2, 3 and you want to add a new post between 1 and 2, you can use 11 or 15 as the ID for that post without changing the other post IDs.