docs(Grids): updated spacer example to use v-spacer (#9303)
docs(Grids): updated spacer example to use v-spacer (#9303)

updated the old v-spacer syntax of a div with class="flex-grow-1" to new syntax of v-spacer
component for the example code in the v-spacer section of the grid documentation
Webifi/vuetify,Webifi/vuetify,vuetifyjs/vuetify,vuetifyjs/vuetify,vuetifyjs/vuetify,vuetifyjs/vuetify,Webifi/vuetify