Added smooth_page_indicator to UI section

[Milad-Akarie]

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Description

Added smooth_page_indicator to UI section, It's so far the number on page indicator on pub.dev

Checklist

• [x] I read How to contribute
• [x] I edited the SOURCE.md file only
• [x] Added a link to the repo in the PR

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[BHamiltonPecks]

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