feat: add search/filter to templates and extensions pages

[ulises-jeremias]

Describe the feature

Client-side search for catalog pages.

Use Case

Harder to find scientific/ML addons as catalog grows.

Proposed Solution

Filter by name/slug/labels.

Other Information

Maintainer-seeded Hacktoberfest issue for Create-Vlang-App website.

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

Version used

website @ main

Environment details (OS name and version, etc.)

n/a