docs: sync CLI dashboard key table

[andrewcb22]

Closes #36.

Updates docs/reference/cli.md so its dashboard key table matches docs/guide/dashboard.md.

Changes include:

• adding the missing enter, d, [, ], and backspace rows
• adding the mouse/click rows present in the dashboard guide
• aligning the existing row descriptions so both tables match in full

Validation:

• Compared the Markdown table rows in docs/reference/cli.md and docs/guide/dashboard.md; they now match exactly.

I could not run cargo fmt or cargo test locally because cargo is not installed in my Windows environment. This change is Markdown-only.