Move the license file into the root folder #723

GitHub automatically detect the license but the file must be called LICENSE.md and be placed in the root folder.
For the website repository I generated the file using a GitHub template => https://github.com/amule-org/amule-org.github.io/blob/main/LICENSE.md
Then you can see the license in the repository.


If you do the change remember to search for references to avoid broken links from other parts of the code / docs.