DOC add FAQ entry for the many linear model classes (#19861)
DOC add FAQ entry for the many linear model classes (#19861)

Co-authored-by: Chiara Marmo <fae0564e6c67e3b55d8e0653c84ab87c92b2657f@users.noreply.github.com>
betatim/scikit-learn,amueller/scikit-learn,espg/scikit-learn,TomDLT/scikit-learn,anntzer/scikit-learn,AlexandreAbraham/scikit-learn,kevin-intel/scikit-learn,ivannz/scikit-learn,saiwing-yeung/scikit-learn,scikit-learn/scikit-learn,jakirkham/scikit-learn,lesteve/scikit-learn,AlexandreAbraham/scikit-learn,vinayak-mehta/scikit-learn,sergeyf/scikit-learn,saiwing-yeung/scikit-learn,scikit-learn/scikit-learn,amueller/scikit-learn,vinayak-mehta/scikit-learn,amueller/scikit-learn,betatim/scikit-learn,huzq/scikit-learn,huzq/scikit-learn,AlexandreAbraham/scikit-learn,TomDLT/scikit-learn,shyamalschandra/scikit-learn,ivannz/scikit-learn,shyamalschandra/scikit-learn,betatim/scikit-learn,TomDLT/scikit-learn,amueller/scikit-learn,anntzer/scikit-learn,scikit-learn/scikit-learn,kevin-intel/scikit-learn,anntzer/scikit-learn,saiwing-yeung/scikit-learn,ivannz/scikit-learn,glemaitre/scikit-learn,vinayak-mehta/scikit-learn,ivannz/scikit-learn,huzq/scikit-learn,shyamalschandra/scikit-learn,jakirkham/scikit-learn,manhhomienbienthuy/scikit-learn,shyamalschandra/scikit-learn,jakirkham/scikit-learn,kevin-intel/scikit-learn,kevin-intel/scikit-learn,lesteve/scikit-learn,glemaitre/scikit-learn,manhhomienbienthuy/scikit-learn,espg/scikit-learn,lesteve/scikit-learn,saiwing-yeung/scikit-learn,manhhomienbienthuy/scikit-learn,huzq/scikit-learn,sergeyf/scikit-learn,jakirkham/scikit-learn,lesteve/scikit-learn,sergeyf/scikit-learn,espg/scikit-learn,betatim/scikit-learn,manhhomienbienthuy/scikit-learn,AlexandreAbraham/scikit-learn,vinayak-mehta/scikit-learn,TomDLT/scikit-learn,glemaitre/scikit-learn,glemaitre/scikit-learn,scikit-learn/scikit-learn,sergeyf/scikit-learn,espg/scikit-learn,anntzer/scikit-learn