Adding a simple .zft example

[kalwalt]

This pull request includes several changes to improve the documentation, update dependencies, and enhance the codebase for better performance and readability. The most important changes include updating the Node.js version requirement, fixing typos, adding new examples, updating dependencies, and enhancing type safety and code clarity.

Documentation Updates:

• CONTRIBUTING.md: Updated the Node.js version requirement from v14 to v20.
• README.md: Fixed a typo in the example file name and added a new example for .zft files. [1] [2] [3]

Example Enhancements:

• examples/arNFT_gltf_flamingo_example.html: Added lang="en" to the HTML tag and replaced var with const for better type safety. [1] [2]
• examples/arNFT_initialize_raw_example.html: Added lang="en" to the HTML tag and replaced var with const for better type safety. [1] [2]
• examples/arNFT_simd_example.html: Added lang="en" to the HTML tag and replaced var with const for better type safety. [1] [2]
• examples/arNFT_zft_example.html: Added a new example file for .zft files.

Dependency Updates:

• package.json: Updated multiple dependencies including @types/node, prettier, typedoc, typescript, webpack, @webarkit/jsartoolkit-nft and @webarkit/oneeurofilter-ts. [1] [2]

Code Enhancements:

• src/ARnft.simd.ts: Improved type safety by replacing var with const, added detailed JSDoc comments, and fixed minor typos. [1] [2] [3] [4] [5] [6] [7] [8] [9]