ckeditor/ckeditor5-basic-styles

{
    "Bold": "Toolbar button tooltip for the Bold feature.",
    "Italic": "Toolbar button tooltip for the Italic feature.",
    "Underline": "Toolbar button tooltip for the Underline feature.",
    "Code": "Toolbar button tooltip for the Code feature.",
    "Strikethrough": "Toolbar button tooltip for the Strikethrough feature.",
    "Subscript": "Toolbar button tooltip for the Subscript feature.",
    "Superscript": "Toolbar button tooltip for the Superscript feature."
}