Document how to add Varbase AI without a Blog content type

Problem/Motivation

• Educare has no Blog content type.
• Varbase AI Taxonomy Tagging, applied by Varbase AI Base, tags blog by default. Applying Varbase AI Base with its default inputs on a Educare site stops with a validation error on field.field.node.blog.field_tags.

Steps to reproduce

• Install Varbase 11 with the Educare site template.
• Run drush recipe ../recipes/varbase_ai_base.

Proposed resolution

• Add an "Add Varbase AI" section to the README: apply Varbase AI Base with --input=varbase_ai_taxonomy_tagging.content_type=news, and link to the docs.

Remaining tasks

• ✅ File an issue
• ✅ Addition/Change/Update/Fix (MR)
• ✅ Testing to ensure no regression: Varbase AI Base applied with content_type=news on a fresh Varbase 11 Educare site
• ➖ Automated unit/functional testing coverage
• ✅ Developer Documentation support
• ➖ User Guide Documentation support
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ❌ Reviewed by a human
• ❌ Code review by maintainers
• ❌ Full testing and approval
• ❌ Credit contributors
• ❌ Review with the product owner
• ✅ Release educare-1.0.9

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• N/A

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