Writing the text

PlainTextAst.cs

public override void AcceptVisitor(IAstVisitor visitor)
{
    if(Parent is RootAst)  // in case it's top level we want to have <p> tag, if it's inside <b> tag we dont need it.
    visitor.BeginVisit(this);
    if(visitor is IAstWriteableVisitor writeableVisitor)
        writeableVisitor.Write(Text);                    /// here you output the text.
    if (Parent is RootAst)
        visitor.EndVisit(this);
}