[css-grid-1][css-grid-2] Add 'display: grid' to examples w3c#11848

Author: fantasai

css-grid-1/Overview.bs

@@ -443,6 +443,7 @@ Declaring the Grid</h3>
 				the last row is given a fixed size of ''30px''.
 				<pre>
 					main {
+					  display: grid;
 					  grid: "H    H "
 					        "A    B "
 					        "F    F " 30px
@@ -460,10 +461,12 @@ Declaring the Grid</h3>
 
 				<pre>
 					main {
+					  display: grid;
 					  grid: repeat(auto-fill, 5em) / auto-flow 1fr;
 					  height: 100vh;
 					}
 					@media print {
+					  display: grid;
 					  main {
 					    grid: auto-flow 1fr / repeat(auto-fill, 5em);
 					  }
@@ -477,8 +480,9 @@ Declaring the Grid</h3>
 
 				<pre>
 					main {
-						grid: auto 1fr auto / repeat(5, 1fr);
-						min-height: 100vh;
+					  display: grid;
+					  grid: auto 1fr auto / repeat(5, 1fr);
+					  min-height: 100vh;
 					}
 				</pre>
 		</ul>
@@ -546,6 +550,7 @@ Sizing the Grid</h3>
 
 		<pre>
 			main {
+				display: grid;
 				grid: auto-flow 1fr / repeat(auto-fill, 5em);
 				min-height: 100vh;
 				justify-content: space-between;

css-grid-2/Overview.bs

@@ -444,6 +444,7 @@ Declaring the Grid</h3>
 				the last row is given a fixed size of ''30px''.
 				<pre>
 					main {
+					  display: grid;
 					  grid: "H    H "
 					        "A    B "
 					        "F    F " 30px
@@ -461,6 +462,7 @@ Declaring the Grid</h3>
 
 				<pre>
 					main {
+					  display: grid;
 					  grid: repeat(auto-fill, 5em) / auto-flow 1fr;
 					  height: 100vh;
 					}
@@ -478,8 +480,9 @@ Declaring the Grid</h3>
 
 				<pre>
 					main {
-						grid: auto 1fr auto / repeat(5, 1fr);
-						min-height: 100vh;
+					  display: grid;
+					  grid: auto 1fr auto / repeat(5, 1fr);
+					  min-height: 100vh;
 					}
 				</pre>
 		</ul>
@@ -547,6 +550,7 @@ Sizing the Grid</h3>
 
 		<pre>
 			main {
+				display: grid;
 				grid: auto-flow 1fr / repeat(auto-fill, 5em);
 				min-height: 100vh;
 				justify-content: space-between;