Add a guide on spawning processes for backend plugins using the 'child_process' node.
New Guide: Add src/guides/backend/subprocess.md with explanations and examples on spawning processes, reading stdout and stderr, waiting for process to close, and using shell: true or shell: '/bin/bash' options.
Index Update: Modify src/guides/index.md to include a link to the new guide under a new "Backend" section.
Sidebar Update: Modify .vitepress/sidebars/guides.ts to add a "Backend" section with a link to the new "Spawning a subprocess" guide.
Fixes #9
Add a guide on spawning processes for backend plugins using the 'child_process' node.
src/guides/backend/subprocess.mdwith explanations and examples on spawning processes, reading stdout and stderr, waiting for process to close, and usingshell: trueorshell: '/bin/bash'options.src/guides/index.mdto include a link to the new guide under a new "Backend" section..vitepress/sidebars/guides.tsto add a "Backend" section with a link to the new "Spawning a subprocess" guide.For more details, open the Copilot Workspace session.