fix: resolve navigation highlighting between Community and Documentation

[labdhiongithub7]

Fixes #456

Changes

• Moved Community page to a standalone page
• Fixed navigation highlighting issue
• Updated styling for better consistency

Before Changes

After Changes

Testing

• Verified navigation highlighting works correctly
• Tested on different screen sizes
• Checked all links

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[labdhiongithub7]

@ameijer could you please review this also!

[ameijer]

@labdhiongithub7 can you give us a test plan to help view the changeset here vs the prod opencost site?

[labdhiongithub7]

@labdhiongithub7 can you give us a test plan to help view the changeset here vs the prod opencost site?

Sure @ameijer ,
Previously, when navigating to the Community section, both Community and Documentation navbar items were highlighted.
This happened because the Community content lived under the docs/ directory, so Docusaurus treated it as part of the Documentation plugin and marked both items active.

What changed

Moved Community content from docs/ to a standalone page under src/pages/community
Updated navbar routing accordingly
Kept styling consistent

Result

Visiting /community now highlights only the Community tab
Documentation is no longer incorrectly marked active
Navigation behavior matches user expectation

How to verify

Open production site and click Community
-- Observe both Community and Documentation are highlighted
Open deploy preview and click Community
-- Only Community is highlighted