Docs: Dropdown fixes

[louismaximepiton]

Note: Please transform - [ ] into - (NA) in the description when things are not applicable

Related issues

NA

Description

Use .nav-link instead of .btn in a navbar.
Remove the cut border on split-dropdown when in show.
Remove border on .nav-link since we declare border on each nav.

Motivation & Context

Be closer to Bootstrap.
Fix some issues in the doc

Types of change

• Bug fix (non-breaking which fixes an issues)
• Refactoring (non-breaking change)

Live previews

• https://deploy-preview-1793--boosted.netlify.app/docs/components/dropdowns#dark-dropdowns (second example)
• https://deploy-preview-1793--boosted.netlify.app/docs/components/navs-tabs

Checklist

Contribution

• I have read the contributing guidelines

Accessibility

• My change follows accessibility good practices; I have at least run axe

Design

• My change respects the design guidelines defined in Orange Design System
• My change is compatible with responsive display

Development

• My change follows the developer guide
• (NA) I have added JavaScript unit tests to cover my changes

Documentation

• My change introduces changes to the documentation and/or I have updated the documentation accordingly

Checklist (for Core Team only)

• (NA) My change introduces changes to the migration guide
• (NA) My new component is added in Storybook
• (NA) My new component is compatible with RTL
• Manually run BrowserStack tests
• Manually test browser compatibility with BrowserStack (Chrome >= 60, Firefox >= 60 (+ ESR), Edge, Safari >= 12, iOS Safari, Chrome & Firefox on Android)
• Code review
• Design review
• A11y review

After the merge

• Manually launch Percy tests

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[julien-deramond]

Haven't spotted any issues. No need to mention anything in the migration IMO so let's 🚀

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication