Add bloom filter example using p5.strands under filter() reference

[LalitNarayanYadav]

This PR adds a minimal example of applying a bloom effect using p5.strands inside filter(), as discussed in #7898. The code is added right after the p5.Shader.prototype.modify line in ShaderGenerator.js, keeping it grouped with other strands reference materials.

PR Checklist

• npm run lint passes
• Inline reference is included / updated
• Unit tests are included / updated

[perminder-17]

I can see you’re updating the reference. A few tips: you’ve added a JS sketch in shaderGenerator.js, but you also need to include the YUI docs as described on the “Contributing to the p5.js reference” page on the beta site. Here: https://beta.p5js.org/contribute/contributing_to_the_p5js_reference/

To preview how your changes look on the website, follow the “Testing the docs of your fork” instructions in the scripts.md in the p5.js-website repo. https://github.com/processing/p5.js-website/blob/main/docs/scripts.md#testing-the-docs-of-your-fork

Let me know if I can help in anything if something finds difficult for you. Thanks for your great work so far on p5.Strands, really appreciated.