Add Eleva.js to Front-end JavaScript frameworks collection

Eleva.js is an ultra-lightweight (~2.5KB) pure vanilla JavaScript frontend framework for building single-page applications.

Key features:
- Signal-based reactivity
- Zero dependencies
- No build step required
- TypeScript support built-in
- Plugin system (Router, Store, Attr)

Repository: https://github.com/TarekRaafat/eleva
Website: https://elevajs.com
npm: https://www.npmjs.com/package/eleva

Author: TarekRaafat

collections/front-end-javascript-frameworks/index.md

@@ -32,6 +32,7 @@ items:
  - sveltejs/kit
  - refinedev/refine
  - docusign/1fe
+ - TarekRaafat/eleva
 
 display_name: Front-end JavaScript frameworks
 created_by: jonrohan