The reason you include the license in your project is so that if the person clones the repo or downloads the tar.gz/zip, they get the license with it, even if it is offline.

While it is a kind thing to try to do this for folks, linking to a license is not a good idea.

Also, while it isn't as commonplace as it was in the early 2000s, legally, I'm told it is still the best idea to include the license in every file of your project where there is significant value. I don't personally think the clutter is worth it, but then again, I've not written something so important that if the license were pissed upon that I would "gather guns" and sue.

Additionally, even though MIT is still bread and butter as far as I'm concerned (and I'm a Ruby guy and Rails, etc. use it), some claim Apache is better if you are concerned about the strength of the license.