How to make contenteditable editor in ReactJS with text conversion back to json file?

Question

JavaScript

Good afternoon!
A string comes to my input, which I parse and break into lexemes, as a result I get a two-dimensional array, where each element of the array is an object that should be in the string.
Example:

[
  // первая строка
  [
    {type: 'text', value: 'Привет'},
    {type: 'tag', value: 'get_users'},
  ],
  // вторая строка
  [
    {type: 'text', value: 'мир'},
  ],
]

What I output: I mark all tags as contenteditable="false" so they can be easily removed
How it renders:

<div contenteditable="true" class="textarea">
  <div>Привет <span class="tag tag-blue" contenteditable="false">get_users</span></div>
  <div>мир</div>
</div>

Questions

1. How can I edit a line in a json file when editing a line?
   
2. If, for example, the user wants to add a text field behind the get_users tag, how do I understand this event and add a new type of text behind an object with type tag in a two-dimensional array?
   

To summarize: How can I learn to edit the desired object in the array and add a new one if necessary, or by line break?