Indicate license, Create `LICENSE` file and update `README`

[abetusk]

This project looks great!

I see from the pictures that there is an open source hardware logo on the board. In the following I assume the intent is that this project is an open source hardware project and that the intent was to include the source files under a free/libre license.

Without license information, the default is that the appropriate digital artifacts fall under copyright. For each of the digital artifacts in the project, including source code, documentation and design files, an appropriate license should be chosen. When an appropriate license is chosen for each, it should be indicated in the documentation (for example, the README file) and a LICENSE file.

Source code should have a header indicating which license it falls under. Also be wary of using third party libraries that are not free/libre. I notice the CH552.INC is copyright W.ch, so that could be a problem for you or others wanting to use that library. If there are non-free/libre libraries that need to be included you should indicate which parts of the project are not free/libre so others can avoid their usage when extending your project.

The Open Source Hardware Association has created a helper web page to create project "facts" for ease of readability. I have generated a graphic that could be used for you project, should you agree with the licensing, but you can. of course, generate your own should you want different licensing.

The Open Source Hardware Association has guidelines on best practices for an open source hardware project in English and in Chinese. GNU.org has some recommendations on how to apply software licenses as well (also available in Chinese).

It would also be good to provide some pictures (like the ones shown on your Twitter account) in the initial landing README page so that people can immediately see what the project is about.

[wuxx]

thanks for the good advice, will improve the README and license :)