Build Linux Chapter 18 artifact

Workflow runs for Build Linux Chapter 18 artifact

• Fix Chapter 18 sidebar matcher bootstrap

  completed successfully:
  Build Linux Chapter 18 artifact#3:Commit33e2662pushedbymohammadijoo
  chatgpt/linux-chapter18-artifact-20260805

  Aug 5, 202615s
  More actions for workflow run 3

• Support formatted Chapter 18 sidebar markup

  failed:
  Build Linux Chapter 18 artifact#2:Commitf7c82a6pushedbymohammadijoo
  chatgpt/linux-chapter18-artifact-20260805

  Aug 5, 202617s
  More actions for workflow run 2

• Add Chapter 18 artifact validation workflow

  failed:
  Build Linux Chapter 18 artifact#1:Commitd7a08a9pushedbymohammadijoo
  chatgpt/linux-chapter18-artifact-20260805

  Aug 5, 202611s
  More actions for workflow run 1