Scripts: Fix typo in readme

[swissspidy]

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Why?

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Testing Instructions

Testing Instructions for Keyboard

Screenshots or screencast

[github-actions]

Flaky tests detected in 954761f.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/6596355126
📝 Reported issues:

• [Flaky Test] Save flow should work as expected. #36943 in specs/site-editor/multi-entity-saving.test.js
• [Flaky Test] allows conversion back to blocks when the reusable block has unsaved edits #44601 in specs/editor/various/pattern-blocks.test.js
• [Flaky Test] can be created, inserted, edited and converted to a regular block. #35977 in specs/editor/various/pattern-blocks.test.js
• [Flaky Test] can be inserted after refresh #55509 in specs/editor/various/pattern-blocks.test.js
• [Flaky Test] can be saved when modified inside of a published post #55507 in specs/editor/various/pattern-blocks.test.js
• [Flaky Test] should allow a block with styles to be converted to a reusable block #44332 in specs/editor/various/pattern-blocks.test.js
• [Flaky Test] will not break the editor if empty #49440 in specs/editor/various/pattern-blocks.test.js