Shortcuts App (iOS 13.1.1): How can I realize a text output in a bigger font size, a specific color, font-weight, ...?
I found the solution on my own.

The steps are:


Action "Text": Insert the code of a complete HTML web page
Action "Create formatted text from HTML"
Action "Overview": Show the variable "Formatted text to HTML"


The names of the action may vary, because I use an iOS in german language and do not know the exact names of actions in english.

Hint: The content, which you write into the element "title" will be shown as the title of the window "overview".

If you like to test the shortcut:
https://www.icloud.com/shortcuts/4ecffecad4dd42ccac909a15b3a08fd8