Introduce wireit 'lint' command

[kwangure]

The Wireit VS Code extension is extremely helpful for immediately spotting errors in the open package.json. If you modify a package.json such that it is correct, but it invalidates the correctness of another that's not open you wont see it that error. A wireit lint command checks all packages would be a helpful addition to git hooks or CI linting.

[leadoflife]

Also, Git Hooks and CI could simply build on top of WireIt linting. For example, using a Husky git hook to call WireIt's linting command

[luke-lacroix-healthy]

In addition to what was stated above, I would also like to add that not everyone uses VSCode.

Are there any maintainers that can weigh in on this? Would a PR be accepted? Or is the expectation that this would be handled by an external tool, much in the way that the VSCode extension is external to wireit?