qr scanning: add comments to distinguish qrscanner.py and qrreader/

electrum/qrreader/__init__.py

@@ -22,6 +22,8 @@
 # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
+#
+# A module, that, given an image (buffer), finds and decodes a QR code in it.
 
 from typing import Optional