Add one-line explainer of match/maps/rounds/chunks above the table

src/routes/+page.svelte

@@ -350,7 +350,7 @@
 	<!-- Browser -->
 	<section class="mx-auto mt-8 max-w-5xl">
 		<Tabs.Root bind:value={view} class="w-full">
-			<div class="mb-2 flex items-center justify-between gap-2">
+			<div class="mb-1 flex items-center justify-between gap-2">
 				<h2 class="font-heading text-lg font-semibold tracking-tight">Browse the dataset</h2>
 				<Tabs.List>
 					<Tabs.Trigger value="rounds">Rounds</Tabs.Trigger>
@@ -358,6 +358,14 @@
 					<Tabs.Trigger value="matches">Matches</Tabs.Trigger>
 				</Tabs.List>
 			</div>
+			<p class="text-muted-foreground mb-3 text-xs">
+				A <strong class="text-foreground font-semibold">match</strong> is a best-of-N series
+				(usually BO3) of
+				<strong class="text-foreground font-semibold">maps</strong>; each map plays up to 24
+				<strong class="text-foreground font-semibold">rounds</strong> (MR12 regulation + MR3
+				overtime); per player POV every round is sliced into ≤ 1-minute
+				<strong class="text-foreground font-semibold">chunks</strong>.
+			</p>
 
 			{#if data.matches.length === 0}
 				<div class="space-y-2">