Fixing broken links (#267)

Changes:
 * Fallback images links are all lowercase now.
 * Fix html redirect (meta tag http-equiv redirect) from ```/git/clone-commit-via-http ```to ```/git/clone-commit-via-web```.
 * Added protocol to an email link.
 * Fix some pages links.

To detect broken links I used wget:

```
wget --spider --recursive --level=0 --debug -e robots=off --base=http://localhost:8080 http://localhost:8080 2>&1 | grep ^Found\ [0-9]*\ broken\ link
```

However, wget detects html redirects (meta tag http-equiv refresh) as false positive.

If broken links have found, then the referer header will be searched for find out where they are:
```
wget --spider --recursive --level=0 --save-headers --debug -e robots=off --base=http://localhost:8080 http://localhost:8080 2>&1 | less
```

Co-authored-by: fsologureng <sologuren@estudiohum.cl>
Reviewed-on: https://codeberg.org/Codeberg/Documentation/pulls/267
Co-authored-by: Felipe Leopoldo Sologuren Gutiérrez <fsologureng@noreply.codeberg.org>
Co-committed-by: Felipe Leopoldo Sologuren Gutiérrez <fsologureng@noreply.codeberg.org>

content/collaborating/resolve-conflicts.md

@@ -10,7 +10,7 @@ When collaborating with others on a big project, sometimes it occurs that someon
 
 First of all: Do not panic! You should be able to resolve merge conflicts with a little time and patience.
 
-While it is a good idea to rebase your branch before creating a pull request, as described in the article on [Pull requests and Git flow](pull-requests-and-git-flow.md),
+While it is a good idea to rebase your branch before creating a pull request, as described in the article on [Pull requests and Git flow](/collaborating/pull-requests-and-git-flow),
 sometimes merge conflicts are unavoidable.
 
 This article will explain what to do in case of a merge conflict, and how to resolve it using the command line.

content/contact.md

@@ -16,7 +16,7 @@ If you need quicker help or want to freely discuss topics, or follow up on Codeb
 - use the unofficial (community-created) [Codeberg Subreddit](https://www.reddit.com/r/Codeberg/)
 
 ## Email
-For user support on Codeberg.org that *can not be handled by the channels mentioned above* (e.g. because it requires sensitive information), you can send an email to [help@codeberg.org](help-PLEASE-REMOVE-THIS-FOR-SPAM-PROTECTION@codeberg.org).  
+For user support on Codeberg.org that *can not be handled by the channels mentioned above* (e.g. because it requires sensitive information), you can send an email to [help@codeberg.org](mailto:help-PLEASE-REMOVE-THIS-FOR-SPAM-PROTECTION@codeberg.org).  
 If you need to get in touch with the people behind the non-profit Codeberg e.V. (e.g. for managing your membership etc), please instead write to [codeberg@codeberg.org](mailto:codeberg-PLEASE-REMOVE-THIS-FOR-SPAM-PROTECTION@codeberg.org).
 
 ## Legal inquiries

content/getting-started/install-git.md

@@ -86,7 +86,7 @@ If you'd prefer not to store your credentials in Windows but e.g. in a password
 >
 > <picture>
 >   <source srcset="/assets/images/getting-started/install-git/win-error-notes.webp" type="image/webp">
->   <img src="/assets/images/getting-started/install-git/win-error-notes.PNG" alt="win-error">
+>   <img src="/assets/images/getting-started/install-git/win-error-notes.png" alt="win-error">
 > </picture>
 
 ### Run

content/markdown/topics.md

@@ -17,7 +17,7 @@ The Setext provides only two layers of subdivision and the ATX-Style provides up
 
 The Codeberg documentation uses the ATX-style. In the documentation, the first topic
 is omitted as it is already provided in the header section of the documentation file.
-See the article on [How do I create a new article?](/improving-documentation/create-article.md)
+See the article on [How do I create a new article?](/improving-documentation/create-article/)
 for further details.
 
 **Note:** This document may seem a little unstructured, as there are a bunch of topics with only a small