Add prompt to read pdf file

prompts.yaml

@@ -10,6 +10,16 @@
   In the end you have to return a final answer using the `final_answer` tool.
 
   Here are a few examples using notional tools:
+  ---
+  Task: "Extract text from pdf file"
+
+  Thought: I will use the `extract_text_from_pdf` tool to extract the text from the PDF file named 'document.pdf'.
+  Code:
+  ```py
+  text = extract_text_from_pdf(file_path="document.pdf")
+  print(text)
+  ```<end_code>
+  
   ---
   Task: "Generate an image of the oldest person in this document."