Page templates improvements

[andrii-balitskyi]

• Remove italic text
• Fix issue with resource description not being picked up
• Remove "Type" from API route page, use capitalized "Format" only
• Add "Properties" header after resource name in API route layout
• Fix inconsistent heading level rendering
• Include only the first paragraph of endpoint description under each endpoint in the "Endpoints" section
• Move resource description to appear after its name
• Add possible enum values for enum properties