Syntax highlighting for Svelte

[damascene]

Could you please add support for Svelte syntax highlighting. I tried to use HTML markup syntax but it seems to break on some tags like {# each} and {#if}. Probably because of {#.

I've included screenshot and code snippet that may help represent the current situation.

Docs: https://svelte.dev/docs/introduction

<script>
	let count = 0;

	function increment() {
		count += 1;
	}
</script>

<button on:click={increment}>
	Clicked {count}
	{count === 1 ? 'time' : 'times'}
</button>

{#if count > 10}
	<p>{count} is greater than 10</p>
{:else if count < 5}
	<p>{count} is less than 5</p>
{:else}
	<p>{count} is between 5 and 10</p>
{/if}

[elextr]

Syntax highlighting lexers come from the Lexilla project. The lexer would need to be added there first.