feat: add multilingual mode support (#241)

BREAKING CHANGE:  Layout file renamed ´layouts/partials/page-footer.html → layouts/partials/menu-nextprev.html`. If you use overrides, you might need to change the filenames as well.

exampleSite/content/en/features/code-blocks.md

@@ -0,0 +1,95 @@
+---
+title: Code Blocks
+---
+
+There are several ways to add code blocks. Most of them work out of the box, only the Hugo short code `<highlight>` needs to be configured to work properly. The theme also provides some additional features like a copy button and an option to set the maximum length of code blocks. Both of these functions and the dependent formatting rely on the `.highlight` CSS class. You must ensure that you always assign a language to your code blocks if you want to use these functions. If you do not want to apply syntax highlighting, you can also specify `plain` or `text` as the language.
+
+{{< toc >}}
+
+## Inline code
+
+To display an inline shortcode use single quotes:
+
+```plain
+`some code`
+```
+
+**Example:** `some code`
+
+## Code blocks
+
+Code blocks can be uses without language specification:
+
+````markdown
+```Plain
+some code
+```
+````
+
+**Example:**
+
+```Plain
+some code
+```
+
+... or if you need language specific syntax highlighting:
+
+````markdown
+```Shell
+# some code
+echo "Hello world"
+```
+````
+
+**Example:**
+
+```Shell
+# some code
+echo "Hello World"
+```
+
+## Highlight shortcode
+
+Hugo has a build-in shortcode for syntax highlighting. To work properly with this theme, you have to set following options in your site configuration:
+
+{{< tabs "uniqueid" >}}
+{{< tab "TOML" >}}
+
+```TOML
+pygmentsUseClasses=true
+pygmentsCodeFences=true
+```
+
+{{< /tab >}}
+{{< tab "YAML" >}}
+
+```YAML
+pygmentsUseClasses: true
+pygmentsCodeFences: true
+```
+
+{{< /tab >}}
+{{< /tabs >}}
+
+You can use it like every other shortcode:
+
+<!-- prettier-ignore -->
+```markdown
+{{</* highlight Shell "linenos=table" */>}}
+# some code
+echo "Hello World"
+{{</* /highlight */>}}
+```
+
+**Example:**
+
+<!-- markdownlint-disable -->
+
+<!-- prettier-ignore-start -->
+{{< highlight Shell "linenos=table" >}}
+# some code
+echo "Hello World"
+{{< /highlight >}}
+<!-- prettier-ignore-end-->
+
+<!-- markdownlint-enable -->