feat: add interactive Google Maps for event locations

[tam3tamtam-private]

resolves #42

Add Interactive Event Location Maps

Description

Added interactive Google Maps embedded iframes to the "Who Comes" section,
showing the venues where Kyoto Tech Meetup events typically take place. This
helps visitors visualize event locations and discover the community spaces we use.

Changes Made

New Features:

• Two Google Maps iframes displaying FabCafe Kyoto and Starbucks Coffee - Kyoto Nishikikoji
• Square, rounded cards with responsive layout (stacked on mobile, side-by-side on desktop)
• Bilingual descriptions in English and Japanese

Code Improvements:

• Created src/data/event-locations.json to separate data from component logic
• Refactored iframe code to use .map() for scalability
• Used generic "eventLocation" terminology to support cafes, conference rooms, and other venues
• Added accessibility attributes (title and aria-label) for screen readers

Internationalization:

• Added home.locations.description3 translation key to ui.ts (English and Japanese)
• Maps display appropriate descriptions based on selected language

Files Changed

• src/pages/index.astro - Refactored locations section with imported event data
• src/data/event-locations.json - New file with venue information
• src/i18n/ui.ts - Added Japanese translation for map description

Design Details

• Maps are square with aspect-square and rounded corners (rounded-2xl)
• Responsive gap between maps (gap-4)
• Tight spacing between description and maps (pt-2)
• Consistent with existing card styling throughout the site

How to Add New Venues

Simply add a new object to src/data/event-locations.json:

{
  "name": "Venue Name",
  "embedUrl": "https://www.google.com/maps/embed?pb=..."
}