Update themeing docs for more clearly how to remove from map (#25589)
Update themeing docs for more clearly how to remove from map (#25589)

* Add note about insert position of "map-remove"

* Use optional keys instead of required keys

bootstrapbrasil/bootstrap,tjkohli/bootstrap,gijsbotje/bootstrap,inway/bootstrap,Lyricalz/bootstrap,creativewebjp/bootstrap,joblocal/bootstrap,peterblazejewicz/bootstrap,GerHobbelt/bootstrap,stanwmusic/bootstrap,Hemphill/bootstrap-docs,fschumann1211/bootstrap,gijsbotje/bootstrap,seanwu99/bootstrap,GerHobbelt/bootstrap,Hemphill/bootstrap-docs,zalog/bootstrap,coliff/bootstrap,bootstrapbrasil/bootstrap,coliff/bootstrap,zalog/bootstrap,joblocal/bootstrap,creativewebjp/bootstrap,stanwmusic/bootstrap,inway/bootstrap,zalog/bootstrap,yuyokk/bootstrap,twbs/bootstrap,joblocal/bootstrap,Hemphill/bootstrap-docs,fschumann1211/bootstrap,stanwmusic/bootstrap,fschumann1211/bootstrap,Lyricalz/bootstrap,stanwmusic/bootstrap,gijsbotje/bootstrap,yuyokk/bootstrap,tagliala/bootstrap,fschumann1211/bootstrap,joblocal/bootstrap,gijsbotje/bootstrap,m5o/bootstrap,peterblazejewicz/bootstrap,kvlsrg/bootstrap,yuyokk/bootstrap,twbs/bootstrap,bardiharborow/bootstrap,kvlsrg/bootstrap,seanwu99/bootstrap,yuyokk/bootstrap,tagliala/bootstrap,Lyricalz/bootstrap,bootstrapbrasil/bootstrap,m5o/bootstrap,creativewebjp/bootstrap,Hemphill/bootstrap-docs,nice-fungal/bootstrap,bardiharborow/bootstrap,tagliala/bootstrap,seanwu99/bootstrap,tjkohli/bootstrap,nice-fungal/bootstrap,GerHobbelt/bootstrap,peterblazejewicz/bootstrap,nice-fungal/bootstrap,bardiharborow/bootstrap,inway/bootstrap,kvlsrg/bootstrap,creativewebjp/bootstrap,Lyricalz/bootstrap,bardiharborow/bootstrap,seanwu99/bootstrap