fix(cli): Dont -> Don't

[gabegorelick]

See open-constructs/cdk-terrain-docs#14

Related issue

Fixes #

Description

Add missing apostrophe to "Dont"

Checklist

• I have updated the PR title to match CDKTN's style guide
• I have run the linter on my code locally
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation if applicable
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works if applicable
• New and existing unit tests pass locally with my changes