docs: permalinks to headings (#383)

### Summary of Changes

Add button to the right of headings to navigate to a permalink that
points exactly to that heading.

.mega-linter.yml

@@ -3,7 +3,7 @@
 EXTENDS: https://raw.githubusercontent.com/lars-reimann/.github/main/.mega-linter.yml
 
 # Config
-FILTER_REGEX_EXCLUDE: (\.github/workflows/|DSL/com\.larsreimann\.safeds/src/test/resources/)
+FILTER_REGEX_EXCLUDE: (\.github/workflows/|DSL/com\.larsreimann\.safeds/src/test/resources/|mkdocs.yml)
 
 # Workaround to also run prettier on other supported file types. We deactivate it for Markdown compared to the extended
 # configuration since it breaks admonitions of Material for MkDocs.

mkdocs.yml

@@ -124,9 +124,9 @@ markdown_extensions:
       custom_fences:
         - name: mermaid
           class: mermaid
-          format: !!python/name:pymdownx.superfences.fence_code_format # Footnotes
-
+          format: !!python/name:pymdownx.superfences.fence_code_format
 
+  # Footnotes
   - footnotes
 
   # Keys
@@ -135,9 +135,9 @@ markdown_extensions:
   # Icons & emojis
   - pymdownx.emoji:
       emoji_index: !!python/name:materialx.emoji.twemoji
-      emoji_generator: !!python/name:materialx.emoji.to_svg # Images
-
+      emoji_generator: !!python/name:materialx.emoji.to_svg
 
+  # Images
   - attr_list
   - md_in_html
 
@@ -150,7 +150,11 @@ markdown_extensions:
   - pymdownx.arithmatex:
       generic: true
 
+  # Permalinks
+  - toc:
+      permalink: "#"
+
 extra_javascript:
-  - javascripts/mathjax.js
+  - javascript/mathjax.js
   - https://polyfill.io/v3/polyfill.min.js?features=es6
   - https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js