all - new external sample submission

Hello,

I've written an implementation with an architecture that is significantly different to the ones used in this repo. It uses the todo-mvp branch as a base, but there are enough changes to make the two branches not directly comparable. Some of the UI tests run without alteration, others had to be tweaked and some of them completely re-written for example.

I think it's positives are clarity and sparseness of code (even though this particular implementation is coded in Java). I've written the changes up in a [blog post](https://dev.to/erdo/tutorial-android-architecture-blueprints-full-todo-app-mvo-edition-259o) and the repo is [here](https://github.com/erdo/android-architecture).

If you're in agreement I'd like to submit it for consideration in the list of external samples

Review the linked blog post and external repository to understand the proposed sample and how it differs from the todo-mvp branch. Check the repository's existing external-sample listing, if present; this is done when maintainers agree on inclusion and the sample is added to that list.

Written by the indexing model from the issue text.