feat: adding initial spacing token

[georgewrmarshall]

TO DO

• Break out into separate smaller PRs for CSS, CSSinJS and Docs
• Create unit tests for CSS

Description

This PR introduces spacing tokens for Figma JSON, CSS-in-JS, and CSS variables, as well as updates the Storybook documentation. It includes a new SpacingSwatch documentation component to visually represent the spacing tokens in Storybook. This ensures that both developers and designers can easily reference and apply consistent spacing across the design system.

Related issues

Fixes: #732

Manual testing steps

1. Review the generated spacing tokens in Figma JSON, CSS-in-JS, and CSS variables.
2. Check the Storybook documentation for the SpacingSwatch component to ensure it correctly displays the spacing tokens.
3. Ensure the documentation reflects the spacing tokens properly across different formats.
4. Verify that the tokens are consistently applied within the design system.

Screenshots/Recordings

After

spacing1080.mov

Pre-merge author checklist

• I’ve followed MetaMask Coding Standards.
• I've clearly explained what problem this PR is solving and how it is solved.
• I've linked related issues.
• I've included manual testing steps.
• I've included screenshots/recordings if applicable.
• I’ve included tests if applicable.
• I’ve documented my code using JSDoc format if applicable.
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.
• I’ve properly set the pull request status:
  • In case it's not yet "ready for review", I've set it to "draft".
  • In case it's "ready for review", I've changed it from "draft" to "non-draft".

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and/or screenshots.

[metamaskbot]

Builds ready [3bb46d9]

Storybook: Storybook

[metamaskbot]

Builds ready [ea73d57]

Storybook: Storybook

[metamaskbot]

Builds ready [fe83ff4]

Storybook: Storybook

[metamaskbot]

Builds ready [dbfd2b2]

Storybook: Storybook

[metamaskbot]

Builds ready [8daa671]

Storybook: Storybook

[socket-security]

No dependency changes detected. Learn more about Socket for GitHub ↗︎

👍 No dependency changes detected in pull request

[georgewrmarshall]

@SocketSecurity ignore-all

[metamaskbot]

Builds ready [08caa74]

Storybook: Storybook

[georgewrmarshall]

Moved to separate PR #734

[metamaskbot]

Builds ready [faf9365]

Storybook: Storybook