Add pages for SIGs and organization information

[No767]

Summary

Adds the pages for each SIG, and the about page, which contains contact information, and leadership information.

Closes #203 and #201

Types of changes

What types of changes does your code introduce to the UC Merced's ACM Chapter Website?
Put an x in the boxes that apply

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (Updates to README.md, the documentation, etc)
• Other (if none of the other choices apply)

Checklist

Put an x in the boxes that apply

• If code changes were made then they have been tested.
• All workflows pass with my new changes
• This PR does not address a duplicate issue or PR

[netlify]

✅ Deploy Preview for ucmacm ready!

Name	Link
🔨 Latest commit	c412dfa
🔍 Latest deploy log	https://app.netlify.com/projects/ucmacm/deploys/69fe73303899ad0008192032
😎 Deploy Preview	https://deploy-preview-765--ucmacm.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.
Lighthouse	1 paths audited Performance: 92 Accessibility: 97 Best Practices: 92 SEO: 83 PWA: 80 View the detailed breakdown and full score reports

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud