[docs] correct typos and update broken documentation links

[harshitpawar64]

✨ Description

This PR addresses documentation quality issues:

• Fixed multiple typos throughout the codebase
• Corrected broken documentation links in both CONTRIBUTING.md and the PR template

These fixes help keep our docs and code comments clean and accurate without affecting functionality.

🔍 Type of change

Select all that apply:

• 🐛 Bug fix (non-breaking change that addresses a specific issue)
• 🚀 New feature (non-breaking change that adds functionality)
• ⚠️ Breaking change (a change that could affect existing functionality)
• 📈 Performance improvement/optimization (improves speed, memory usage, or efficiency)
• 🛠️ Code refactor (non-functional changes that improve code readability, structure, etc.)
• 📦 Dependency bump (updates dependencies, including Dockerfile or package changes)
• 📝 Documentation change (link fixes and typo corrections)
• 🔧 Infrastructure/Build change (affects build process, CI/CD, or dependencies)

📝 Changes

List the key changes introduced in this PR:

1. Fixed typos in:

   • setup.cfg
   • config.py
   • utils.py
   • mamba_layer.py
   • discrete_mamba2.py
   • preprocessing.py
   • huggingface.py

2. Updated broken links in:

   • CONTRIBUTING.md
   • .github/PULL_REQUEST_TEMPLATE.md

✅ Checklist

Make sure the following tasks are completed before submitting the PR:

General

• 📜 I have read and followed the contributing guidelines.
• 🏷️ I am using a clear and descriptive PR title that summarizes the key change or feature introduced.
• 🎉 The functionality is complete, and I have tested the changes.
• 📝 I have updated the documentation if needed.
• ⚠️ The change does not introduce any new issues (e.g., runtime warnings, type checker errors, linting problems, unhandled edge cases).
• 🧩 I have commented my code, especially in hard-to-understand areas.

Testing

• ✔️ New and existing tests pass locally with my changes. (no functionality changed)

Performance Impact

• ✅ No performance impact (documentation-only changes)

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[jlamypoirier]

LGTM, thanks!