Feature/worker threads generation (#43)

* Add worker threads architecture plan for blog generation

* fix: tries to optimize rendering, still slow

* feat: moved site rendering into web worker

* fix: calendar grabs from central data source for calendar

* fix: feeds now use blog language content and not canonical content

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Co-authored-by: hugo <hugoms@me.com>

src/renderer/types/highlightjs-cdn-assets.d.ts

@@ -0,0 +1,4 @@
+declare module '@highlightjs/cdn-assets/es/highlight.min.js' {
+  import hljs from 'highlight.js';
+  export default hljs;
+}