Fix formatting in README for build instructions

[kavix]

Description

Related Issues

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring / Code quality improvement

Technical Details & Architecture Notes

How Has This Been Tested?

• Run go test -v ./... results:

Checklist

• My code follows the style guidelines of this project (run gofmt and go vet)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (including README.md and CONTRIBUTING.md)
• My changes generate no new compiler or linter warnings
• I have added/updated unit tests that prove my fix is effective or that my feature works
• All new and existing unit tests pass locally with my changes