Increase the WebAssembly heap size to accommodate larger fonts

Fixes Munter/subfont#145

index.js

@@ -9,7 +9,7 @@ const loadAndInitializeHarfbuzz = _.once(async () => {
   } = await WebAssembly.instantiate(
     await readFile(require.resolve('harfbuzzjs/subset/hb-subset.wasm'))
   );
-  exports.memory.grow(400); // each page is 64kb in size
+  exports.memory.grow(2000); // each page is 64kb in size
 
   const heapu8 = new Uint8Array(exports.memory.buffer);
   return [exports, heapu8];