hotfix(docs): fix cannonfile spec docs

[mjlescano]

This PR includes changes on the https://website-lrrh8g5w8-cannon.vercel.app/learn/cannonfile section.

1. Fixes the deployers key documentation
2. Updates the Constants section with real data
3. Adds a section for Utilities
4. When referencing step types, instead of writing pull write it as [pull.*] to make it more clear that is a step name and differentiate it from other sections

[changeset-bot]

⚠️ No Changeset found

Latest commit: 3d02ef6

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