org-project: Capture TODOs in project.el using org-mode

Hi! This is my first emacs package, vastly inspired from [org-projectile](https://github.com/IvanMalison/org-projectile) but designed around [project.el](https://www.gnu.org/software/emacs/manual/html_node/emacs/Projects.html) instead of [projectile](https://github.com/bbatsov/projectile) The goals is to quickly capture TODO items in org-mode for the current project, and then be able to find them back quickly. It is not yet feature-complete, but does enough that it can be useful for others. Comments and advices appreciated!

This is a very useful project. Thanks for doing it. Regarding the documentation, it may help to add a link to your complete configuration, or to a bunch of complete configs from other people. Please document org-project-per-project-file and org-project-projects-file. If time permits, create a simple screencast to showcase the use of the package. Finally, perhaps add the TODO.org for this project to the GitHub entry.

Looks very nice! Will give it a try.

org-projectile author here... did you consider using org-projectile's org-category-capture? ​ It was designed for EXACTLY something like this so that the backend for actually capturing things could be shared between projects. ​ I don't really care much since I don't use org-mode anymore, but sharing code in cases like this is generally a lotbetter

> did you consider using org-projectile's org-category-capture? I used to, before dicthing it for two simple reasons: - I'm still finding my footing in elisp & the emacs APIs, so sdding the whole CL-object layer/capture strategies on top of it was a bit overwhelming; - I didn't need the category properties in the org entries, so it was a bit overkill for simple capture.