Fix broken link in README

[0awful]

What is the purpose of this pull request? (put an "X" next to item)

[X] Documentation update [ ] Bug fix [ ] New feature [ ] Other, please explain:

What changes did you make? (Give an overview) added www. to BEP 44 link.

Which issue (if any) does this pull request address? Broken Link within readme

Is there anything you'd like reviewers to focus on?

[welcome[bot]]

🙌 Thanks for opening this pull request! You're awesome.

[welcome[bot]]

🎉 Congrats on getting your first pull request landed!

[webtorrent-bot]

:tada: This PR is included in version 11.0.5 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: