feat(GUI): add a more user-friendly summary to merge log

index.html

@@ -205,6 +205,14 @@ <h1>bitsy-merge</h1>
 				output.value = merged.gamedata;
 				log.value = `Merged successfully!
 
+Summary:
+${Object.values(merged.added).reduce((sum, i) => sum + Object.keys(i).length, 0) ?
+	Object.entries(merged.added).map(([map, entries]) => {
+		const keys = Object.keys(entries);
+		return keys.length ? `- Added ${keys.length} ${keys.length === 1 ? map.substring(0, map.length-1) : map}: ${keys.join(', ')}` : undefined
+	}).filter(i => i).join('\n')
+	: 'Nothing changed!'}
+
 Detail:
 ${JSON.stringify({ added: merged.added, skipped: merged.skipped }, (key, value) => key === 'world' ? undefined : value, 2)}`;
 			} catch (error) {