Update README.md since https://yt-dl.org/ got taken down by law.

[PalmarHealer]

Removed all links to https://yt-dl.org/ because it got taken down a few months ago. There is an issue talking about this: #32495

Please follow the guide below

• You will be asked some questions, please read them carefully and answer honestly
• Put an x into all the boxes [ ] relevant to your pull request (like that [x])
• Use Preview tab to see how your pull request will actually look like

---

Before submitting a pull request make sure you have:

• Searched the bugtracker for similar pull requests
• Read adding new extractor tutorial
• Read youtube-dl coding conventions and adjusted the code to meet them
• Covered the code with tests (note that PRs without tests will be REJECTED)
• Checked the code with flake8

In order to be accepted and merged into youtube-dl each piece of code must be in public domain or released under Unlicense. Check one of the following options:

• I am the original author of this code and I am willing to release it under Unlicense
• I am not the original author of this code but it is in public domain or released under Unlicense (provide reliable evidence)

What is the purpose of your pull request?

• Bug fix
• Improvement
• New extractor
• New feature

---

Description of your pull request and other information

Since https://yt-dl.org/ got taken down by German law I want to have the installation links pointing to the files and not to a dead site. So I changed that they are now directly from GitHub. I don't think it needs no further explaining. There is an issue where it was talked about it: #32495

[dirkf]

Eventually the domain will be reset to point to a valid page.

Meanwhile, I hope it's OK to point to your README.

[PalmarHealer]

If this was a question to me. You can use it, that was the purpose.