Dynamically add styles to text

[vijayk1989]

Is your feature request related to a problem? Please describe.
I want to auto underline text after typing based on a criteria. For example. I have an array with the names: [Jane, John]. Now when I type the word Jane or John I want that text to be underlined after I finish typing them.
I know its possible to add styles to selected text so I tried something similar with a debounced function to add an underline to a word dyanmically but I have been unable to make it work.

Describe the solution you'd like
I want to be able to add styles to text (not selected text) any text in the document.

Describe alternatives you've considered
I have tried scanning the full document and applying styles but I am not able to make it work.