Updated discord links closes #2274

[zafar-hussain]

Description of Change

Checklist

• [x] Added description of change
• [ ] Added file name matches File name guidelines
• [ ] Added tests and example, test must pass
• [ ] Added documentation so that the program is self-explanatory and educational - Doxygen guidelines
• [x] Relevant documentation/comments is changed or added
• [ ] PR title follows semantic commit guidelines
• [ ] Search previous suggestions before making a new one, as yours may be a duplicate.
• [x] I acknowledge that all my contributions will be made under the project's license.

Notes:

with reference to issue #2274 "[OTHER] Update Discord links", four discord links were updated to https://the-algorithms.com/discord/

[zafar-hussain]

hi @Panquesito7

Please if you can check and advice on this PR

cheers