Add System Verilog style guide link in coding standards prompt

[krushideep]

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• My contribution adds a new instruction, prompt, or chat mode file in the correct directory.
• The file follows the required naming convention.
• The content is clearly structured and follows the example format.
• I have tested my instructions, prompt, or chat mode with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.

Description

This PR adds reference to system verilog style guide in the coding standard prompt to improve coverage for hardware design projects

Changes

• Updates write-coding-standards-from-file.prompt.md
• Adds link https://github.com/lowRISC/style-guides/blob/master/VerilogCodingStyle.md under "Fetch links"

Type of Contribution

• New instruction file.
• New prompt file.
• New chat mode file.
• New collection file.
• Update to existing instruction, prompt, chat mode, or collection.
• Other (please specify):

Additional Notes

By submitting this pull request, I confirm that my contribution abides by the Code of Conduct and will be licensed under the MIT License.

[Copilot]

Pull request overview

This PR enhances the coding standards prompt to include SystemVerilog/Verilog support by adding a reference to the lowRISC style guide. The change expands hardware design project coverage alongside existing software language style guides.

Key changes:

• Added System Verilog Style Guide link to the list of language-specific style guides
• Fixed trailing whitespace on several lines