Add footer to ask people to cite armadillo paper

[marikaris]

Demo:

• link in footer of armadillo
• link on the CAS
• link in the docs

Acc:

• citation link
• acknowledgement sentence
• little snippet for the methods section?
• add the footer in the UI

[marikaris]

Citing in the footer fixed in #816

[timcadman]

Full citation

Tim Cadman, Mariska K Slofstra, Marije A van der Geest, Demetris Avraam, Tom R P Bishop, Tommy de Boer, Liesbeth Duijts, Sido Haakma, Eleanor Hyde, Vincent Jaddoe, Tarik Karramass, Fleur Kelpin, Yannick Marcon, Angela Pinot de Moira, Dick Postma, Clemens Tolboom, Ruben L Veenstra, Stuart Wheater, Marieke Welten, Rebecca C Wilson, Erik Zwart, Morris Swertz, MOLGENIS Armadillo: a lightweight server for federated analysis using DataSHIELD, Bioinformatics, Volume 41, Issue 1, January 2025, btae726, https://doi.org/10.1093/bioinformatics/btae726