practice challenge on grid
- grid-template-rows
- grid gap
- grid-auto-row
- grid-auto-column
- grid-template-area:
'nav' 'nav' 'nav'
'content''nav''side'
'footer''footer''footer' - justify-content
- align-items
- display
- grid-column: i.e 1/3
- grid-row:2/4
- grid area:nav;
- align-self:end,center,start
- justify-self