feat: add comprehensive VHS demo tapes for STRUCT features

- Add 8 VHS tape files demonstrating key STRUCT capabilities
- Include basic-usage.tape for core commands (list, info, generate)
- Add yaml-config.tape showing custom YAML configuration creation
- Include mappings-demo.tape for external mappings and template variables
- Add multiple-mappings.tape showcasing new deep merge feature
- Include advanced-features.tape for dry-run, file strategies, validation
- Add remote-content.tape for GitHub/HTTP content fetching
- Include schema-generation.tape for IDE integration support
- Add comprehensive README.md with tape documentation and usage instructions
- Update GitHub Actions workflow to generate all tapes automatically

These tapes provide visual documentation for users to understand
STRUCT's capabilities through animated GIF demonstrations.

Author: httpdss

.github/workflows/generate-terminal-gifs.yaml

@@ -13,6 +13,13 @@ jobs:
       matrix:
         tapes:
           - 'docs/vhs/install.tape'
+          - 'docs/vhs/basic-usage.tape'
+          - 'docs/vhs/yaml-config.tape'
+          - 'docs/vhs/mappings-demo.tape'
+          - 'docs/vhs/multiple-mappings.tape'
+          - 'docs/vhs/advanced-features.tape'
+          - 'docs/vhs/remote-content.tape'
+          - 'docs/vhs/schema-generation.tape'
     runs-on: ubuntu-latest
     steps:
       - name: Checkout