fix: this.document and this.location.href do not exist in a Web Worker (

#55)

* this -> self

this.location does not work in a web worker, but self.location does work both
in a web worker and in a normal page.

* document doesn't exist either

* use self which works in both places

* polyfilling self.document always works

src/index.ts

@@ -134,7 +134,7 @@ export default function topLevelAwait(options?: Options): Plugin {
         newEntry.code = (
           await esbuild.transform(
             // Polyfill `document.currentScript.src` since it's used for `import.meta.url`.
-            `this.document = { currentScript: { src: this.location.href } };\n${newEntry.code}`,
+            `self.document = { currentScript: { src: self.location.href } };\n${newEntry.code}`,
             {
               minify,
               target: buildTarget as string | string[]