Real-time preview mode and sync scroll

[nasdan]

• Right now in ./src/pages/trainer/training/edit/editor.tsx, there is a textarea component to write markdown and a button in ToolbarComponent to preview this content.

• The aim of this issue is preview content while your are writting markdown.

• Also, it's necessary to get sync preview and edit textArea scrolls while you are scrolling one of them. (Maybe this code could be usefull for it).

• Important: Follow this work flow