If you're really serious about this, I'd like to suggest ".project.el" or "project.el" over an unadorned ".project" to avoid clashing with third-party software that uses .project files or directories for its own purposes.

On Fri, Oct 11, 2024 at 5:20 PM Dmitry Gutov <dmitry@gutov.dev> wrote:
On Fri, Oct 11, 2024, at 7:40 PM, Ship Mints wrote:
I assume you're not suggesting adding ".project" to everyone's Emacs default configurations. It's a user option already (which I do use).
I am - if it helps avoid this recurring question.