[TYPO3-doc] Please add 'ser' as allowed extension to the upload filter

[Daniel Brüßler]

Hello, Michiel,

thanks :-)

kind regards
Daniel

> Hi Daniel,
> 
> Thank you.
> 
> I like the new look of the notes template by the way!
> 
> Cheers,
> 
> 
> Michiel Roos
>