Add new detailed guidance category for DCLG.
user
```ruby
MainstreamCategory.create!(
  parent_tag: "business/funding-debt",
  parent_title: "Funding and debt",
  title: "European regional development funding",
  slug: "european-regional-development-funding",
  description: "Advice on the potential of projects and their eligibility for funding from European Regional Development Fund (ERDF), including information on applying for funding in specific region."
)
```
assistant