Add .gitignore for SvelteKit project

[notthecloudy]

Link to the application or project's homepage

https://svelte.dev/docs/kit

Reasons for making this change

SvelteKit is a widely used web application framework, but there is currently no dedicated SvelteKit template in this repository.

This adds a SvelteKit.gitignore template based on the .gitignore used by the official SvelteKit starter template.

The template includes SvelteKit-specific generated directories such as /.svelte-kit/ and /build/, as well as the framework's supported deployment output directories and Vite-generated timestamp files.

A dedicated template makes it easier for SvelteKit users to create an appropriate .gitignore without having to combine generic JavaScript/Node.js templates with framework-specific rules.

Links to documentation supporting these rule changes
Official SvelteKit repository: https://github.com/sveltejs/kit
Official SvelteKit starter template: https://github.com/sveltejs/kit-template-default
Official SvelteKit starter .gitignore: https://github.com/sveltejs/kit-template-default/blob/main/.gitignore
SvelteKit documentation: https://svelte.dev/docs/kit

Merge and Approval Steps

• I have read the contribution guidelines and understand my PR will be closed if it doesn't meet these guidelines