Update MarkdownTokens.svelte: Revert text-align for download button in rtl

prevent button overriding because the download button is in absolute position and it doesn't have start/end properties

src/lib/components/chat/Messages/Markdown/MarkdownTokens.svelte

@@ -118,7 +118,7 @@
 									class="px-3! py-1.5! cursor-pointer border border-gray-100 dark:border-gray-850"
 									style={token.align[headerIdx] ? '' : `text-align: ${token.align[headerIdx]}`}
 								>
-									<div class="flex flex-col gap-1.5 text-start">
+									<div class="flex flex-col gap-1.5 text-left">
 										<div class="shrink-0 break-normal">
 											<MarkdownInlineTokens
 												id={`${id}-${tokenIdx}-header-${headerIdx}`}