Add Proper Import Error (#13042)

- **Description:** The issue was not listing the proper import error for
amazon textract loader.
- **Issue:** Time wasted trying to figure out what to install...
(langchain docs don't list the dependency either)
  - **Dependencies:** N/A
  - **Tag maintainer:** @sbusso 
  - **Twitter handle:** @h9ste

---------

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>

libs/langchain/langchain/document_loaders/parsers/pdf.py

@@ -476,8 +476,10 @@ class AmazonTextractPDFParser(BaseBlobParser):
                 self.textract_features = []
         except ImportError:
             raise ImportError(
-                "Could not import amazon-textract-caller python package. "
-                "Please install it with `pip install amazon-textract-caller`."
+                "Could not import amazon-textract-caller or "
+                "amazon-textract-textractor python package. Please install it "
+                "with `pip install amazon-textract-caller` & "
+                "`pip install amazon-textract-textractor`."
             )
 
         if not client: