feat(cli): support configPath cwd

[JamesLefrere]

• Add support for easily running the CLI from a local build (without linking) by exposing the cwd for all relevant commands, fixing the TODO in buildSystemsManifest. The cwd is obtained through the configPath for the project.
• Standardise interface for foundry commands with execa
• Add documentation for the CLI, including local development and debugging (it's cleaner to run the TypeScript directly rather than build and link, I found)

[changeset-bot]

⚠️ No Changeset found

Latest commit: a5b96a3

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR