docs: translate German comments and docstrings to English

Translate all inline comments, docstrings, and documentation from German to English across the codebase to improve accessibility for international developers.

Fixes #27

Signed-off-by: Nicolai Buchwitz <n.buchwitz@kunbus.com>

tests/revpi3/test_connect.py

@@ -48,7 +48,7 @@ class TestRevPiConnect(TestRevPiModIO):
             with self.assertRaises(ValueError):
                 rpi.core.A3 = BLUE
 
-            # Direkte Zuweisung darf nicht funktionieren
+            # Direct assignment must not work
             with self.assertRaises(AttributeError):
                 rpi.core.a3green = True
             with self.assertRaises(AttributeError):

tests/revpi3/test_core.py

@@ -97,7 +97,7 @@ class TestRevPiCore(TestRevPiModIO):
         with self.assertWarnsRegex(Warning, r"equal device name '.*' in pictory configuration."):
             rpi = self.modio(configrsc="config_old.rsc")
 
-        # Errorlimits testen, die es nicht gibt (damals None, jetzt -1)
+        # Test error limits that don't exist (formerly None, now -1)
         self.assertEqual(rpi.core.errorlimit1, -1)
         self.assertEqual(rpi.core.errorlimit2, -1)