docs[patch]: Adds PDF ingestion and QA tutorial

docs/core_docs/docs/how_to/document_loader_pdf.mdx

@@ -15,9 +15,9 @@ npm install pdf-parse
 ## Usage, one document per page
 
 ```typescript
-import { PDFLoader } from "langchain/document_loaders/fs/pdf";
+import { PDFLoader } from "@langchain/community/document_loaders/fs/pdf";
 // Or, in web environments:
-// import { WebPDFLoader } from "langchain/document_loaders/web/pdf";
+// import { WebPDFLoader } from "@langchain/community/document_loaders/web/pdf";
 // const blob = new Blob(); // e.g. from a file input
 // const loader = new WebPDFLoader(blob);
 
@@ -29,7 +29,7 @@ const docs = await loader.load();
 ## Usage, one document per file
 
 ```typescript
-import { PDFLoader } from "langchain/document_loaders/fs/pdf";
+import { PDFLoader } from "@langchain/community/document_loaders/fs/pdf";
 
 const loader = new PDFLoader("src/document_loaders/example_data/example.pdf", {
   splitPages: false,
@@ -49,7 +49,7 @@ npm install pdfjs-dist
 ```
 
 ```typescript
-import { PDFLoader } from "langchain/document_loaders/fs/pdf";
+import { PDFLoader } from "@langchain/community/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
@@ -63,7 +63,7 @@ PDFs come in many varieties, which makes reading them a challenge. The loader pa
 if you are seeing excessive spaces, this may not be the desired behavior. In that case, you can override the separator with an empty string like this:
 
 ```typescript
-import { PDFLoader } from "langchain/document_loaders/fs/pdf";
+import { PDFLoader } from "@langchain/community/document_loaders/fs/pdf";
 
 const loader = new PDFLoader("src/document_loaders/example_data/example.pdf", {
   parsedItemSeparator: "",

docs/core_docs/docs/integrations/document_loaders/file_loaders/pdf.mdx

@@ -11,7 +11,7 @@ npm install pdf-parse
 ## Usage, one document per page
 
 ```typescript
-import { PDFLoader } from "langchain/document_loaders/fs/pdf";
+import { PDFLoader } from "@langchain/community/document_loaders/fs/pdf";
 
 const loader = new PDFLoader("src/document_loaders/example_data/example.pdf");
 
@@ -21,7 +21,7 @@ const docs = await loader.load();
 ## Usage, one document per file
 
 ```typescript
-import { PDFLoader } from "langchain/document_loaders/fs/pdf";
+import { PDFLoader } from "@langchain/community/document_loaders/fs/pdf";
 
 const loader = new PDFLoader("src/document_loaders/example_data/example.pdf", {
   splitPages: false,
@@ -41,7 +41,7 @@ npm install pdfjs-dist
 ```
 
 ```typescript
-import { PDFLoader } from "langchain/document_loaders/fs/pdf";
+import { PDFLoader } from "@langchain/community/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
@@ -55,7 +55,7 @@ PDFs come in many varieties, which makes reading them a challenge. The loader pa
 if you are seeing excessive spaces, this may not be the desired behavior. In that case, you can override the separator with an empty string like this:
 
 ```typescript
-import { PDFLoader } from "langchain/document_loaders/fs/pdf";
+import { PDFLoader } from "@langchain/community/document_loaders/fs/pdf";
 
 const loader = new PDFLoader("src/document_loaders/example_data/example.pdf", {
   parsedItemSeparator: "",

docs/core_docs/docs/integrations/document_loaders/web_loaders/pdf.mdx

@@ -27,7 +27,7 @@ npm install pdfjs-dist
 ```
 
 ```typescript
-import { WebPDFLoader } from "langchain/document_loaders/web/pdf";
+import { WebPDFLoader } from "@langchain/community/document_loaders/web/pdf";
 
 const blob = new Blob(); // e.g. from a file input
 
@@ -43,7 +43,7 @@ PDFs come in many varieties, which makes reading them a challenge. The loader pa
 if you are seeing excessive spaces, this may not be the desired behavior. In that case, you can override the separator with an empty string like this:
 
 ```typescript
-import { WebPDFLoader } from "langchain/document_loaders/web/pdf";
+import { WebPDFLoader } from "@langchain/community/document_loaders/web/pdf";
 
 const blob = new Blob(); // e.g. from a file input
 

docs/core_docs/docs/tutorials/index.mdx

@@ -21,6 +21,7 @@ New to LangChain or to LLM app development in general? Read this material to qui
 - [Build a Query Analysis System](/docs/tutorials/query_analysis)
 - [Build a local RAG application](/docs/tutorials/local_rag)
 - [Build a Question Answering application over a Graph Database](/docs/tutorials/graph)
+- [Build a PDF ingestion and Question/Answering system](/docs/tutorials/pdf_qa/)
 
 ### Specialized tasks