Special characters handling

* Fix README for python version
* Add discord-friendly unidecode function for channel names (avoiding
  special characted)
* Check if "items" is present before accessing in channel id request
  response

breadtube_bot/unidecode.py

@@ -0,0 +1,19 @@
+import re
+
+from breadtube_bot.unidecode_data import UNIDECODE_DICT
+
+
+DISCORD_PATTERN = re.compile(r'[^a-zA-Z0-9\-_]')
+
+
+def unidecode(text: str) -> str:
+    result: list[str] = []
+    for char in text:
+        codepoint: int = ord(char)
+        if codepoint < 0x80:  # noqa: PLR2004
+            result.append(DISCORD_PATTERN.sub('_', char).lower())
+        elif codepoint >> 8 in UNIDECODE_DICT:
+            result.append(UNIDECODE_DICT[codepoint >> 8][codepoint % 256])
+        else:
+            result.append('_')
+    return ''.join(result)