feat: Make describe view vertically scrollable

[shvbsle]

Problem

Currently the describe output view uses pagination (pages with dots), which is a poor user experience for reading resource descriptions. Users have to navigate between pages instead of smoothly scrolling through content.

Solution

Replace pagination with vertical scrolling using a viewport component. Users should be able to:

• Scroll up/down with j/k or arrow keys
• Jump to top with g, bottom with G
• Smooth scrolling experience similar to less/vim

Related

• Part of improving the describe viewing experience
• Similar change needed for logs view (feat: Make logs view vertically scrollable #73)