Fix cli about missing comma

[NA-V10]

Why:

Improves the grammar and readability of the “About GitHub CLI” documentation.
A missing comma after an introductory clause made the sentence grammatically incorrect.

What's being changed:

• Added a comma after the introductory phrase “If you tend to work on the command line,”.
• This helps align the page with GitHub Docs style guidelines.
• Documentation-only change.

Check off the following:

• A subject matter expert (SME) has reviewed the technical accuracy (grammar-only fix).
• The changes meet documentation fundamentals.
• All CI checks are passing.

[github-actions]

How to review these changes 👓

Thank you for your contribution. To review these changes, choose one of the following options:

• Spin up a codespace
• Set up a local development environment

A Hubber will need to deploy your changes internally to review.

Table of review links

Note: Please update the URL for your staging server or codespace.

The table shows the files in the content directory that were changed in this pull request. This helps you review your changes on a staging server. Changes to the data directory are not included in this table.

Source	Review	Production	What Changed
github-cli/github-cli/about-github-cli.md	fpt ghec ghes@ 3.19 3.18 3.17 3.16 3.15 3.14	fpt ghec ghes@ 3.19 3.18 3.17 3.16 3.15 3.14
github-cli/github-cli/quickstart.md	fpt ghec ghes@ 3.19 3.18 3.17 3.16 3.15 3.14	fpt ghec ghes@ 3.19 3.18 3.17 3.16 3.15 3.14
github-cli/github-cli/using-multiple-accounts.md	fpt ghec ghes@ 3.19 3.18 3.17 3.16 3.15 3.14	fpt ghec ghes@ 3.19 3.18 3.17 3.16 3.15 3.14

Key: fpt: Free, Pro, Team; ghec: GitHub Enterprise Cloud; ghes: GitHub Enterprise Server

🤖 This comment is automatically generated.

[kbackpeople-jpg]

6821b63

[github-actions]

A stale label has been added to this pull request because it has been open 30 days with no activity. If you think this pull request should remain open, please add a new comment.