[Idea][Editor] Add basic shortcut keys when the editor is selected

While typing, users, specially who is used not to touch the mouse during all the writing process prefer to use shortcut combo keys such as:

• CTRL + B for bold
• CTRL + I for italic
• CTRL + S for strikethrough
• CTRL + L for a hiperlink (or a list item)
• ...

Also:
Shift + Enter could write {space}{space}{enter} (just like in WYSIWYG/RTE editors, office, open office, libre office, etc...)