[css-round-display] Update the devcie-radius description(2)

Author: hyojinLGE

css-round-display/Overview.bs

@@ -68,7 +68,7 @@ By the mechanism of media queries, if the value of the 'device-radius' media fea
 Note: To define a '<code>range</code>' type media feature, the feature may be written as a normal media feature, but with a '<code>min-</code>' or '<code>max-</code>' prefix on the feature name. '<code>min-</code>' or '<code>max-</code>' prefixes express 'greater or equal to' or 'smaller or equal to' constraints respectively.
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 <p>
-The length or percentage value of the '<code>device-radius</code>' property defines a radius of a quarter ellipse in terms of the shape of the corner of the outer screen edge (This is similar to the '<code>border-radius</code>' property. See the 'border-radius' description). If the length is zero, the shape of screen is a rectangle, otherwise it is a rectangle with rounded corners or a circle or an ellipse. A percentage value of the '<code>device-radius</code>' is proportional to a width and a height of the screen, which affects horizontal radius of the screen and vertical radius of the screen each. If the screen shape is the regular circle, '<code>device-radius</code>': 50% has a true value, because a half of the width(=height) of the regular circle is the radius of the screen shape. In case of an ellipse with 200x100, '<code>device-radius</code>': 50% means that horizontal-radius of the screen is 100px and vertical-radius of the screen is 50px. It can't be described in length, not percentage. A negative value is not allowed.
+The length or percentage value of the '<code>device-radius</code>' property defines a radius of a quarter ellipse in terms of the shape of the corner of the outer screen edge (This is similar to the '<code>border-radius</code>' property. See the 'border-radius' description). If the length is zero, the shape of screen is a rectangle, otherwise it is a rectangle with rounded corners or a circle or an ellipse. A percentage value of the '<code>device-radius</code>' is proportional to a width and a height of the screen, which affects a horizontal radius of the screen and a vertical radius of the screen each. If the screen shape is the regular circle, '<code>device-radius</code>': 50% has a true value since a half of the width(=height) of the regular circle is the radius of the screen shape. In case of an ellipse with 200x100, '<code>device-radius</code>': 50% means that horizontal-radius of the screen is 100px and vertical-radius of the screen is 50px. It can't be described in length, not percentage. A negative value is not allowed.
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 <div class='example'>