📚 Document generic placeholder approach in README

✅ TEMPLATE PHILOSOPHY UPDATED:
- Documents justfile.template generic placeholders
- Explains the three customizable command types:
  - {{DATA_DOWNLOAD_COMMAND}} - Project data download logic
  - {{DBT_RUN_COMMAND}} - dbt run with project variables
  - {{DBT_TEST_COMMAND}} - dbt test with project variables

✅ CLEAR SEPARATION:
- .github/ = STABLE (CI/CD framework)
- .squirro/ = SQUIRRO-SPECIFIC (integration tools)
- deployment/ = CUSTOMIZABLE (config files)
- justfile.template = GENERIC (task structure with placeholders)

Template now provides true genericity while maintaining structure.

Author: ppolydoras

README.md

@@ -159,7 +159,12 @@ git push origin main
 ## Template Philosophy
 
 - **`.github/` = STABLE** - Rarely changes, provides consistent CI/CD
+- **`.squirro/` = SQUIRRO-SPECIFIC** - Tools and workflows for Squirro integration
 - **`deployment/` = CUSTOMIZABLE** - Projects modify configuration files
+- **`justfile.template` = GENERIC** - Uses placeholders for project-specific commands:
+  - `{{DATA_DOWNLOAD_COMMAND}}` - How to download your project's data
+  - `{{DBT_RUN_COMMAND}}` - How to run dbt with your data variables
+  - `{{DBT_TEST_COMMAND}}` - How to test dbt with your data variables
 - **Clear separation** - Teams know exactly what to customize vs what to keep
 
 ## Examples