Wrong timezone for GMT+-X conversion

[Edwardhk]

Issue:

The timezone output of the gmt+x and gmt-x seems to be swapped.
For the reference, Hong Kong is in GMT+8.

Step to reproduce:

$ timezone-converter --version
timezone-converter 0.12.1

$ timezone-converter hong_kong gmt-5 gmt+5

┏━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━┓
┃      LOCAL       ┃  ASIA/HONG_KONG  ┃    ETC/GMT-5     ┃    ETC/GMT+5     ┃
┡━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━┩
│ 2022-11-24 00:00 │ 2022-11-24 00:00 │ 2022-11-23 21:00 │ 2022-11-23 11:00 │
│ 2022-11-24 01:00 │ 2022-11-24 01:00 │ 2022-11-23 22:00 │ 2022-11-23 12:00 │
│ 2022-11-24 02:00 │ 2022-11-24 02:00 │ 2022-11-23 23:00 │ 2022-11-23 13:00 │
│ 2022-11-24 03:00 │ 2022-11-24 03:00 │ 2022-11-24 00:00 │ 2022-11-23 14:00 │
│ 2022-11-24 04:00 │ 2022-11-24 04:00 │ 2022-11-24 01:00 │ 2022-11-23 15:00 │
...

[ibLeDy]

Sorry, I don't have free time to review this issue right now. Feel free to submit a PR if you want to tackle the issue tho!