refactor: replace static strings with calls to getVisibleText

[Alexander Alemayhu]

The plan is to translate the website to German and possibly other languages. So I have added basic support for fetching strings from a JSON document. Now we just need to use it consistently. If you are interested in contributing to this, below is an example.

Example

So basically the changes are to replace all texts with calls to getVisibleText. You need to come up with keys and add them to the JSON document src/lib/text/app.document.json.

Before

<p>Some text</p>

After

<p>{getVisibleText('theKey')}</p>