This is simple text that you can copy & paste into your calendar tool of choice to help explain to meeting organizers why you are declining a meeting they have invited you to.
I once created a repository by the same name when I worked for a large enterprise as a middle manager. In that role, I was invited to far more meetings than my poor little calendar could deal with. And it gave me no time at all to get my actual work done, or to manage my department, without putting in long nights and weekends.
I was resolved to take my time back. And so I noticed many of the meetings that I was being invited to were easy to decline based on some common themes.
Rather than overthink every single response, I would copy and paste boilerplate text from my GitHub repository.
And I found that my coworkers appreciated this and began using it, as well.
Now I'm in a more senior position at another company, running into some of the same themes. I've been mentioning my old justsayno repository quite a lot. So I thought it was time to re-create it, but this time using my personal GitHub account so that I won't lose sight of it again.