Fix open API styles in dark mode

[w666]

Close #207

Description

Fix dark color scheme when display tables in rendered open api spec, now background is the same as on other pages in dark mode.

Fixes #207

Type of change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📝 Documentation update

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings