Bump to syntect 5.0.0 to e.g. start lazy-loading syntaxes (#2181)

* Bump to syntect 5.0.0 to e.g. start lazy-loading themes

Closes #915
Closes #951
Closes #1846
Closes #1854

* Typo fix formated -> formatted

* Update CHANGELOG.md

tests/syntax-tests/source/Svelte/App.svelte

@@ -27,9 +27,13 @@
 </script>
 
 <script type="text/livescript">
-    // This block is a regression test for a bat panic when a LiveScript syntax definition is missing
+	// This block is a regression test for a bat panic when a LiveScript syntax definition is missing
 </script>
 
+<style lang="text/postcss">
+	/* This block is a regression test for a bat panic when a PostCSS syntax definition is missing */
+</style>
+
 <style>
 	main {
 		position: relative;

tests/syntax-tests/source/Vue/example.vue

@@ -8,6 +8,11 @@
   </div>
 </template>
 
+<template lang='pug'>
+  #container.col
+    p This shall be formatted as Plain Text as long as a Pug syntax definition is missing
+</template>
+
 <script>
 import AppHeader from "@/components/AppHeader";
 import AppLoadingIndicator from "@/components/AppLoadingIndicator";