Using Add-Content cmdlet you can append data to a text/html file.
Example
        `0 -- Null
        `a -- Alert
        `b -- Backspace
        `n -- New line
        `r -- Carriage return
        `t -- Horizontal tab
        `' -- Single quote
        `" -- Double quote
    
    you can find more details at 
    Powershell language special characters