InputRichBlockSectionHeading
A section heading, corresponding to the HTML tags <h1>, <h2>, <h3>, <h4>, <h5>, or <h6>.
Fields
typeString = headingRequiredType of the block, always "heading"
Text of the block
sizeIntegerRequiredRelative size of the text font; 1-6, 1 is the largest, 6 is the smallest