I export them as .md (markdown).

It turns them into two folders

Resources

NGINX@HOME (The name of my note book)

Resources consists of images.

NGINX@HOME consists of markdown file.

Now, I push them into github using this post

https://stackoverflow.com/a/63645193/19901123

Next time, I write 2nd note on NGINX.

I write it in the same notebook as earlier.

I export it as .md.

Again it makes the two folders with same name as above because the notebook is same.

Now, I want to to push that code to github to the same repository.

But when I try it I get various errors.

    error: failed to push some refs to 'https://github.com/<my_github_id>/my_notes.git'
    hint: Updates were rejected because the remote contains work that you do
    hint: not have locally. This is usually caused by another repository pushing
    hint: to the same ref. You may want to first integrate the remote changes
    hint: (e.g., 'git pull ...') before pushing again.
    hint: See the 'Note about fast-forwards' in 'git push --help' for details.

    fatal: refusing to merge unrelated histories