Sort election in a more advanced way

See merge request stustanet/wahlfang!34

* removed double shadow in the election view
* reduced default value for election to 5 min
* removed old todos

spectator links for elections, issue #25

See merge request stustanet/wahlfang!32

Explain green mail addresses, issue #24

See merge request stustanet/wahlfang!31

export prometheus metrics

Closes #12

See merge request stustanet/wahlfang!30

resolves issue #6: generalization of applicants to options except self apply is activated

Closes #6

See merge request stustanet/wahlfang!29

multiple doc improvements

See merge request stustanet/wahlfang!28

removed stusta domain references in the code and moved it to the config file, moved default email address (used when no manger email is set) to the settings file

issue #22: prints qr code of the meeting link onto the pdf when available

See merge request stustanet/wahlfang!27

issue #22: prints qr code of the meeting link onto the pdf when available, removed json export since its redundant and one small model label update

fixed pylint errors and disabled pipeline failure of pylint

See merge request stustanet/wahlfang!26

Datetimepicker Issue #11

See merge request stustanet/wahlfang!24

small fixes in session settings, added datetime picker in session settings, small ui fix in sessions view