Port #18530 to v4
Port #18530 to v4

Docs: Include major version in `npm install bootstrap` commands
Future-proofing for when Bootstrap v5 eventually exists.
Refs #18520

[ci skip]

tagliala/bootstrap,twbs/bootstrap,copperdesign/bootstrap,m5o/bootstrap,inway/bootstrap,david-schopf/bootstrap,fschumann1211/bootstrap,tibo66/bootstrap,bardiharborow/bootstrap,tomlutzenberger/bootstrap,bardiharborow/bootstrap,creativewebjp/bootstrap,hebbet/bootstrap,edanbarak/bootstrap,hebbet/bootstrap,nice-fungal/bootstrap,vsn4ik/bootstrap,realcrowd/bootstrap,Hemphill/bootstrap-docs,abvalentine/bootstrap,NCARB/bootstrap,seanwu99/bootstrap,realcrowd/bootstrap,tomlutzenberger/bootstrap,vsn4ik/bootstrap,seanwu99/bootstrap,JumpLinkNetwork/bootstrap-backward,onenameio/rhythm-bootstrap,Hemphill/bootstrap-docs,davethegr8/bootstrap,yuyokk/bootstrap,seanwu99/bootstrap,Hemphill/bootstrap-docs,9-chirno/chirno,yuyokk/bootstrap,wesamco/bootstrap-rtl,Hemphill/bootstrap-docs,afuno/bootstrap,9-chirno/chirno,igoynawamreh/bootstrap,copperdesign/bootstrap,lipis/bootstrap,IdanCo/bootstrap,NCARB/bootstrap,Delagen/bootstrap,supergibbs/bootstrap,xt0rted/bootstrap,hebbet/bootstrap,Scoutski/bootstrap,stanwmusic/bootstrap,onenameio/rhythm-bootstrap,SweetProcess/bootstrap,jipexu/bootstrap,inway/bootstrap,nice-fungal/bootstrap,IdanCo/bootstrap,yuyokk/bootstrap,coliff/bootstrap,JumpLinkNetwork/bootstrap-backward,fschumann1211/bootstrap,copperdesign/bootstrap,TheFridayInstitute/bootstrap,Scoutski/bootstrap,hebbet/bootstrap,Delagen/bootstrap,afuno/bootstrap,gijsbotje/bootstrap,gijsbotje/bootstrap,blockstack/blockstack-bootstrap,andresgalante/bootstrap,tjkohli/bootstrap,creativewebjp/bootstrap,joblocal/bootstrap,lemuelbarango/bootstrap,JumpLinkNetwork/bootstrap-backward,Lyricalz/bootstrap,sealocal/bootstrap,realcrowd/bootstrap,inway/bootstrap,janseliger/bootstrap,andresgalante/bootstrap,onenameio/rhythm-bootstrap,frostbitten/bootstrap,janseliger/bootstrap,lemuelbarango/bootstrap,Hightrack/bootstrap,IdanCo/bootstrap,andresgalante/bootstrap,NCARB/bootstrap,lipis/bootstrap,n054/bootstrap,davethegr8/bootstrap,IdanCo/bootstrap,creativewebjp/bootstrap,igoynawamreh/bootstrap,peterblazejewicz/bootstrap,slavanga/bootstrap,kvlsrg/bootstrap,bardiharborow/bootstrap,wesamco/bootstrap-rtl,wesamco/bootstrap-rtl,bootstrapbrasil/bootstrap,fschumann1211/bootstrap,TheFridayInstitute/bootstrap,copperdesign/bootstrap,stanwmusic/bootstrap,creativewebjp/bootstrap,xt0rted/bootstrap,vitaligent/4,Scoutski/bootstrap,peterblazejewicz/bootstrap,SweetProcess/bootstrap,supergibbs/bootstrap,m5o/bootstrap,lemuelbarango/bootstrap,sealocal/bootstrap,igoynawamreh/bootstrap,yuyokk/bootstrap,sealocal/bootstrap,wesamco/bootstrap-rtl,andresgalante/bootstrap,tomlutzenberger/bootstrap,gijsbotje/bootstrap,supergibbs/bootstrap,frostbitten/bootstrap,frostbitten/bootstrap,blockstack/blockstack-bootstrap,Delagen/bootstrap,zalog/bootstrap,Hightrack/bootstrap,edanbarak/bootstrap,SweetProcess/bootstrap,vsn4ik/bootstrap,jipexu/bootstrap,tibo66/bootstrap,bootstrapbrasil/bootstrap,janseliger/bootstrap,jipexu/bootstrap,joblocal/bootstrap,9-chirno/chirno,blockstack/blockstack-bootstrap,Scoutski/bootstrap,GerHobbelt/bootstrap,GerHobbelt/bootstrap,afuno/bootstrap,vitaligent/4,TheFridayInstitute/bootstrap,NCARB/bootstrap,zalog/bootstrap,abvalentine/bootstrap,edanbarak/bootstrap,kvlsrg/bootstrap,stanwmusic/bootstrap,slavanga/bootstrap,tibo66/bootstrap,twbs/bootstrap,igoynawamreh/bootstrap,Lyricalz/bootstrap,afuno/bootstrap,tibo66/bootstrap,kvlsrg/bootstrap,GerHobbelt/bootstrap,johnajacob/bootstrap,Lyricalz/bootstrap,zalog/bootstrap,seanwu99/bootstrap,bootstrapbrasil/bootstrap,9-chirno/chirno,Delagen/bootstrap,frostbitten/bootstrap,TheFridayInstitute/bootstrap,SweetProcess/bootstrap,realcrowd/bootstrap,johnajacob/bootstrap,Hightrack/bootstrap,tjkohli/bootstrap,david-schopf/bootstrap,slavanga/bootstrap,tagliala/bootstrap,bardiharborow/bootstrap,slavanga/bootstrap,peterblazejewicz/bootstrap,nice-fungal/bootstrap,JumpLinkNetwork/bootstrap-backward,joblocal/bootstrap,n054/bootstrap,david-schopf/bootstrap,janseliger/bootstrap,lipis/bootstrap,abvalentine/bootstrap,coliff/bootstrap,davethegr8/bootstrap,johnajacob/bootstrap,gijsbotje/bootstrap,abvalentine/bootstrap,davethegr8/bootstrap,stanwmusic/bootstrap,edanbarak/bootstrap,fschumann1211/bootstrap,n054/bootstrap,lemuelbarango/bootstrap,jipexu/bootstrap,xt0rted/bootstrap,vitaligent/4,xt0rted/bootstrap,Lyricalz/bootstrap,sealocal/bootstrap,vsn4ik/bootstrap,lipis/bootstrap,tagliala/bootstrap,n054/bootstrap,supergibbs/bootstrap,joblocal/bootstrap,johnajacob/bootstrap