Update css for classTables v3

- add "- spell slots per spell level -" header to full class tables
- add rules for `.classTables.full` which is similar to `wide` but adds the previously mentioned header as well.
- add css variable `--row-color` so the odd row colors can be set in the inline moustache syntax easily.

themes/5ePhb.style.less

@@ -526,7 +526,25 @@ body {
 	h5{
 		margin-bottom : 10px;
 	}
+	&.full{
+		column-span   : all;
+		--row-color   : ;
+		&:after{
+			content		: '— Spell Slots per Spell Level —';
+			font-weight	: bold;
+			font-family	: ScalySans;
+			position	: absolute;
+			top		: 20px;
+			right		: 43px;
+		}
+	}
+	tbody tr:nth-child(odd) {
+		background    : var(--row-color);
+	}
 }
+
+
+
 //*****************************
 // *      TABLE OF CONTENTS
 // *****************************/