fix mypy error

src/extract_otp_secrets.py:707: error: Argument 1 to "save" of "PyPNGImage" has incompatible type "str"; expected "SupportsWrite[bytes]"  [arg-type]

README.md

@@ -779,6 +779,11 @@ FileNotFoundError: Could not find module 'libiconv.dll' (or one of its dependenc
 * [Android OTP Extractor](https://github.com/puddly/android-otp-extractor) can extract your tokens from popular Android OTP apps and export them in a standard format or just display them as QR codes for easy importing. [Requires a _rooted_ Android phone.]
 * [Google Authenticator secret extractor](https://github.com/krissrex/google-authenticator-exporter) is similar project written in JavaScript. It also extracts otp secrets from Google Authenticator.
 
+## Third party documentation
+
+* [TOTP Secret Extraction from QR codes (medium.com)](https://cavalloj.medium.com/totp-secret-extraction-from-qr-codes-ee097b4c687f)
+* [Google Authenticator: OTP-Secrets auslesen (stadt-bremerhaven.de)](https://stadt-bremerhaven.de/google-authenticator-otp-secrets-auslesen/)
+
 ***
 
 # #StandWithUkraine 🇺🇦

src/extract_otp_secrets.py

@@ -49,7 +49,7 @@ from typing import (Any, Final, List, Optional, Sequence, TextIO, Tuple,
                     TypedDict, Union)
 
 import colorama
-from qrcode import QRCode  # type: ignore
+from qrcode import QRCode
 
 import protobuf_generated_python.google_auth_pb2 as pb
 
@@ -704,7 +704,7 @@ def save_qr_image_file(otp_url: OtpUrl, name: str) -> None:
     qr.add_data(otp_url)
     img = qr.make_image(fill_color='black', back_color='white')
     if verbose: print(f"Saving to {name}")
-    img.save(name)
+    img.save(name)  # type: ignore
 
 
 def print_qr(otp_url: str, out: Optional[TextIO] = None) -> None: