Clarify kid format for JWT token auth in docs
Clarify kid format for JWT token auth in docs

The kid value can have an arbitrary format according JOSE specification, but Docker distribution expects a specific format (libtrust fingerprint) to work. This is not written in the documentation so far and is only mentioned in the libtrust source code itself.

Signed-off-by: Fabio Huser <223bb78da41f44447ff0ad216d5a49d6b0f1c366@fh1.ch>

gdevillele/docker.github.io,troy0820/docker.github.io,RichardScothern/distribution,menglingwei/denverdino.github.io,konnase/distribution,cyli/distribution,aduermael/docker.github.io,LuisBosquez/docker.github.io,cyli/distribution,jzwlqx/distribution,liubin/distribution,vdemeester/distribution,aprajshekhar/distribution,docker/distribution,joaofnfernandes/docker.github.io,Seb-Solon/distribution,xiekeyang/distribution,BrianBland/distribution,denverdino/docker.github.io,londoncalling/docker.github.io,thaJeztah/distribution,hopkings2008/distribution,gdevillele/docker.github.io,rbarlow/distribution,JimGalasyn/docker.github.io,thaJeztah/docker.github.io,jzwlqx/denverdino.github.io,spacexnice/distribution,LuisBosquez/docker.github.io,alexisbellido/docker.github.io,kmala/distribution,konstruktoid/distribution,Seb-Solon/distribution,miminar/distribution,johnstep/docker.github.io,joeuo/docker.github.io,genedock/distribution,sanscontext/docker.github.io,joeuo/docker.github.io,harrisonfeng/distribution,menglingwei/denverdino.github.io,konnase/distribution,shubheksha/docker.github.io,denverdino/denverdino.github.io,alexisbellido/docker.github.io,jzwlqx/denverdino.github.io,anweiss/docker.github.io,johnstep/docker.github.io,docker/docker.github.io,aduermael/docker.github.io,denverdino/docker.github.io,nwt/distribution,denverdino/docker.github.io,jzwlqx/denverdino.github.io,konstruktoid/distribution,joaofnfernandes/docker.github.io,manoj535/distribution,gdevillele/docker.github.io,docker/distribution,mikebrow/distribution,sergeyfd/distribution,thaJeztah/docker.github.io,docker-zh/docker.github.io,dmcgowan/distribution,phiroict/docker,rillig/docker.github.io,alexisbellido/docker.github.io,noxiouz/distribution,BSWANG/denverdino.github.io,londoncalling/docker.github.io,joaofnfernandes/docker.github.io,phiroict/docker,londoncalling/docker.github.io,JimGalasyn/docker.github.io,estesp/distribution,dmcgowan/distribution,docker/docker.github.io,RichardScothern/distribution,troy0820/docker.github.io,danix800/docker.github.io,sadlil/distribution,rillig/docker.github.io,phiroict/docker,denverdino/docker.github.io,sanscontext/docker.github.io,anweiss/docker.github.io,docker-zh/docker.github.io,danix800/docker.github.io,jwhonce/distribution,jwhonce/distribution,shin-/docker.github.io,schu/distribution,stevvooe/distribution,docker-zh/docker.github.io,BSWANG/denverdino.github.io,nwt/distribution,johnstep/docker.github.io,alexisbellido/docker.github.io,shubheksha/docker.github.io,spacexnice/distribution,rillig/docker.github.io,cezarsa/distribution,manoj535/distribution,alexisbellido/docker.github.io,yuwaMSFT2/distribution,joaofnfernandes/docker.github.io,thaJeztah/docker.github.io,danix800/docker.github.io,londoncalling/docker.github.io,johnstep/docker.github.io,bdwill/docker.github.io,aprajshekhar/distribution,docker/docker.github.io,bdwill/docker.github.io,shubheksha/docker.github.io,duglin/distribution,troy0820/docker.github.io,shubheksha/docker.github.io,phiroict/docker,BSWANG/denverdino.github.io,sadlil/distribution,dobril-stanga/distribution,docker/docker.github.io,stevvooe/distribution,rbarlow/distribution,joaofnfernandes/docker.github.io,yuwaMSFT2/distribution,joeuo/docker.github.io,anweiss/docker.github.io,sergeyfd/distribution,huamai-io/distribution,bdwill/docker.github.io,joeuo/docker.github.io,sanscontext/docker.github.io,aduermael/docker.github.io,troy0820/docker.github.io,sanscontext/docker.github.io,duglin/distribution,shubheksha/docker.github.io,LuisBosquez/docker.github.io,jzwlqx/denverdino.github.io,shin-/docker.github.io,vdemeester/distribution,LuisBosquez/docker.github.io,denverdino/denverdino.github.io,BrianBland/distribution,mattrgreen/distribution,kmala/distribution,sanscontext/docker.github.io,shyr/distribution,denverdino/docker.github.io,dobril-stanga/distribution,schu/distribution,johnstep/docker.github.io,estesp/distribution,mikebrow/distribution,anweiss/docker.github.io,menglingwei/denverdino.github.io,denverdino/denverdino.github.io,shyr/distribution,phiroict/docker,denverdino/denverdino.github.io,hopkings2008/distribution,anweiss/docker.github.io,danix800/docker.github.io,JimGalasyn/docker.github.io,menglingwei/denverdino.github.io,londoncalling/docker.github.io,xiekeyang/distribution,mbentley/distribution,huamai-io/distribution,jzwlqx/distribution,thaJeztah/docker.github.io,genedock/distribution,bdwill/docker.github.io,harrisonfeng/distribution,noxiouz/distribution,jzwlqx/denverdino.github.io,mattrgreen/distribution,denverdino/denverdino.github.io,docker/docker.github.io,JimGalasyn/docker.github.io,joeuo/docker.github.io,miminar/distribution,docker-zh/docker.github.io,thaJeztah/docker.github.io,gdevillele/docker.github.io,mbentley/distribution,JimGalasyn/docker.github.io,liubin/distribution,shin-/docker.github.io,LuisBosquez/docker.github.io,cezarsa/distribution,rillig/docker.github.io,menglingwei/denverdino.github.io,gdevillele/docker.github.io,docker-zh/docker.github.io,aduermael/docker.github.io,bdwill/docker.github.io,shin-/docker.github.io,BSWANG/denverdino.github.io,thaJeztah/distribution,BSWANG/denverdino.github.io,shin-/docker.github.io