Add one more alternative for loading PDFLoader

docs/docs/modules/indexes/document_loaders/examples/file_loaders/pdf.md

@@ -32,12 +32,31 @@ const docs = await loader.load();
 
 ## Usage, legacy environments
 
-In legacy environments, you can use the `pdfjs` option to provide a function that returns a promise that resolves to the `PDFJS` object. This is useful if you want to use a custom build of `pdfjs-dist` or if you want to use a different version of `pdfjs-dist`. Eg. here we use the legacy build of `pdfjs-dist`, which includes several polyfills that are not included in the default build.
+In legacy environments, you can use the `pdfjs` option to provide a function that returns a promise that resolves to the `PDFJS` object. This is useful if you want to use a custom build of `pdfjs-dist` or if you want to use a different version of `pdfjs-dist`.
+
+Here we use the legacy build of `pdfjs-dist`, which includes several polyfills not included in the default build.
 
 ```typescript
 import { PDFLoader } from "langchain/document_loaders/fs/pdf";
 
 const loader = new PDFLoader("src/document_loaders/example_data/example.pdf", {
+  // you may need to add `.then(m => m.default)` to the end of the import
   pdfjs: () => import("pdfjs-dist/legacy/build/pdf.js"),
 });
 ```
+
+Alternatively, if the legacy build of `pdfjs-dist` doesn't work for you, you can use an older version bundled with `pdf-parse`:
+
+```bash npm2yarn
+npm rm pdfjs-dist # if you had installed it before
+npm install pdf-parse
+```
+
+```typescript
+import { PDFLoader } from "langchain/document_loaders/fs/pdf";
+
+const loader = new PDFLoader("src/document_loaders/example_data/example.pdf", {
+  // you may need to add `.then(m => m.default)` to the end of the import
+  pdfjs: () => import("pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js"),
+});
+```