Updated 6 page descriptions from under 100 characters to 120-160 characters to meet SEO best practices. All descriptions now include detailed, keyword-rich content that better describes page content for search engines and users.

Files changed:

• changelog.mdx (37 → 128 chars)
• features/development/code-editor.mdx (64 → 127 chars)
• features/development/terminal.mdx (60 → 123 chars)
• features/development/webcontainer.mdx (58 → 130 chars)
• features/development/developers.mdx (48 → 122 chars)
• prompting/plan-your-app.mdx (52 → 131 chars)