Update README's links to specs

[richiii999]

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[github-actions]

Welcome to the project, @richiii999!

It looks like this is your first contribution. We noticed the DCO (Developer Certificate of Origin) check might fail if your commits aren't signed.

To fix this, please ensure every commit has a Signed-off-by: Name <email> line. You can do this automatically by using the -s flag:
git commit -s -m "Your message"

For existing commits, you can fix them with:
git commit --amend --signoff or git rebase -i HEAD~N --signoff (where N is the number of commits)
The Developer Community DCO guide also provides helpful tips on fixing DCO inconveniences. Setting a commit hook in the git repository will automate adding the DCO signoff.
See https://github.com/p4lang/governance/wiki/P4-DCO-Guidelines for information.