Update CI-Workflow-Update, Requirements und MkDocs-Sync

[Nirus2000]

This pull request updates the CI workflow configuration, refreshes the requirements.txt file with potentially new or updated dependencies, and synchronizes the mkdocs.yml configuration files across different language versions (likely de and en) to ensure consistency in the documentation build process.

• Add "Validate internal links in Markdown" runner
• Add "Validate image links in Markdown" runner
• Remove obsolet Md-files and structure problems
• Image replaced by default theme color (default is the theme “Light”, not “Dark-Mode”)
• Fix Options in de docs
• Synchronization of the installation process German - English

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Hello @buchen and @hug-sch,
Following up on the discussion in issue #130, I would like to gradually improve a few areas to make the project easier to maintain in the long run.

Specifically, I would like to:

• Update the CI workflow to ensure that errors are caught before changes can be merged into master.
• Align and clean up the mkdocs.yml configuration so that we have a uniform and consistent standard across languages.

Adjusting and synchronizing the two languages and their file structures will certainly be a significant task. However, I believe that the current mixed structure of German/English and the differing folder layouts will not scale well in the future.
I plan to tackle this step by step and hope for your understanding and support along the way.
For the CI settings ("branch protection rules"), only @buchen has the rights to adjust them — we can coordinate this together when the time comes.
Thanks in advance!

Regards
Alex

[buchen]

Just saw this one. I will need some time to understand this (big) change with many different aspects.

Briefly looking at it: updating dependencies seems a no brainer, removing empty placeholder pages sounds reasonable, theming is okay, checking links in the GitHub actions - nice.

I am not sure I understand what "Synchronization of the installation process German - English" is.

The "bigger" changes (only pull requests; synced structure) proposed do not seem to part of this pull request. I would also propose to unpack that discussions - one is possible without the other. My 2 cents here: because @hug-sch does the most work, we must keep his workflow efficient

[Nirus2000]

Hello @buchen
Yes, it is possible that you should break down the pull request into individual parts.
Possibly into dependencies, CI Runner and the changes.

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@hug-sch @Sn1kk3r5
I have the external links item in the CI Runner for the image check.
Here I noticed that images run via the gitHub UserID (82599585), which is not a good thing, so I'm only providing this information at the moment.

🔵 Checking external image https://user-images.githubusercontent.com/82599585/116431429-134f2e00-a848-11eb-937a-8bdb0ab967ef.png
🔵 Checking external image https://user-images.githubusercontent.com/82599585/116431458-1a763c00-a848-11eb-994b-dfb4a472f721.png
🔵 Checking external image https://user-images.githubusercontent.com/82599585/116431530-28c45800-a848-11eb-9084-4576d0af24cd.png
🔵 Checking external image https://user-images.githubusercontent.com/82599585/116431840-6e812080-a848-11eb-95ed-f2c1c3e9e7dc.png
🔵 Checking external image https://user-images.githubusercontent.com/82599585/116431887-79d44c00-a848-11eb-8a40-dd845bd7830e.png
🔵 Checking external image https://user-images.githubusercontent.com/82599585/116431930-83f64a80-a848-11eb-873a-10df00c85ca8.png
🔵 Checking external image https://user-images.githubusercontent.com/82599585/116431984-8fe20c80-a848-11eb-823f-4af73b74ec4e.png
🔵 Checking external image https://user-images.githubusercontent.com/82599585/116432053-9d979200-a848-11eb-93d7-ef3e288a87d3.png

However, we should still adapt the CI runner, the py script, as we can also edit the *.md's online, so that we no longer allow image URL's with https://user-images.githubusercontent.com/.... and prevent the merging in the master for images that begin with this URL.
To do this, however, we would have to replace these images in the documentation.

[hug-sch]

However, we should still adapt the CI runner, the py script, as we can also edit the *.md's online, so that we no longer allow image URL's with https://user-images.githubusercontent.com/.... and prevent the merging in the master for images that begin with this URL. To do this, however, we would have to replace these images in the documentation.

I'm sorry but this is too technical for me. However, if it means that every image-link in the documentation should be changed, than this will be very time consuming.

[Nirus2000]

I'm sorry but this is too technical for me. However, if it means that every image-link in the documentation should be changed, than this will be very time consuming.

No, only these 8 images are from a GitHub user account and should be recreated and uploaded to the structure (appropriate image folder).

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❌ Image issues found:
  [de] In file 'docs/de/how-to/kursdaten_laden.md' at line 25: Image 'https://user-images.githubusercontent.com/82599585/116431429-134f2e00-a848-11eb-937a-8bdb0ab967ef.png' failed (disallowed domain)
  [de] In file 'docs/de/how-to/kursdaten_laden.md' at line 29: Image 'https://user-images.githubusercontent.com/82599585/116431458-1a763c00-a848-11eb-994b-dfb4a472f721.png' failed (disallowed domain)
  [de] In file 'docs/de/how-to/kursdaten_laden.md' at line 33: Image 'https://user-images.githubusercontent.com/82599585/116431530-28c45800-a848-11eb-9084-4576d0af24cd.png' failed (disallowed domain)
  [de] In file 'docs/de/how-to/kursdaten_laden.md' at line 39: Image 'https://user-images.githubusercontent.com/82599585/116431840-6e812080-a848-11eb-95ed-f2c1c3e9e7dc.png' failed (disallowed domain)
  [de] In file 'docs/de/how-to/kursdaten_laden.md' at line 43: Image 'https://user-images.githubusercontent.com/82599585/116431887-79d44c00-a848-11eb-8a40-dd845bd7830e.png' failed (disallowed domain)
  [de] In file 'docs/de/how-to/kursdaten_laden.md' at line 47: Image 'https://user-images.githubusercontent.com/82599585/116431930-83f64a80-a848-11eb-873a-10df00c85ca8.png' failed (disallowed domain)
  [de] In file 'docs/de/how-to/kursdaten_laden.md' at line 51: Image 'https://user-images.githubusercontent.com/82599585/116431984-8fe20c80-a848-11eb-823f-4af73b74ec4e.png' failed (disallowed domain)
  [de] In file 'docs/de/how-to/kursdaten_laden.md' at line 55: Image 'https://user-images.githubusercontent.com/82599585/116432053-9d979200-a848-11eb-93d7-ef3e288a87d3.png' failed (disallowed domain)

[Sn1kk3r5]

No, only these 8 images are from a GitHub user account and should be recreated and uploaded to the structure (appropriate image folder).

@hug-sch @Nirus2000

Hugo, no worries I will take care for it.

IIRC those were there even before we started our work, I guess the git user refers to the one creating the page initially.