docs: update aio->adev links in README, docs and .github dirs

[davidlj95]

PR Checklist

Please check to confirm your PR fulfills the following requirements:

• [x] The commit message follows our guidelines: https://github.com/angular/angular-cli/blob/main/CONTRIBUTING.md#-commit-message-guidelines
• N/A Tests for the changes have been added (for bug fixes / features)
• N/A Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• [ ] Bugfix
• [ ] Feature
• [ ] Code style update (formatting, local variables)
• [ ] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] CI related changes
• [x] Documentation content changes
• [ ] Other... Please describe:

What is the current behavior?

Links in README.md, docs directory and .github directory point to angular.io

Issue Number: N/A

What is the new behavior?

Point to angular.dev

Does this PR introduce a breaking change?

• [ ] Yes
• [x] No

Other information

Related aio -> adev PRs in #27713