AlpineBits HotelData validator backend now also available on GitLab

[Chris Mair]

Hi all,

the validator, that has been online for a long time at:

  https://development.alpinebits.org/#/validator

can now also be used offline!

See the section "Doing your own local validation." that will point you

to the new validator repo at:

  https://gitlab.com/alpinebits/hoteldata/validator

(see Readme.md for details).

Even if you don't use xmllint and my validation scripts, this might be useful

because it contains the official schema files (XSD, RNG and OTA) for all AlpineBits

versions in one single spot.

I'll make sure that the online version and this gitlab repo will always be in sync.

-- Chris