Replaced at="large with greaterThanOrEqual="large"

Based on warnings in the console

src/app.tsx

@@ -538,7 +538,7 @@ class AppComponent extends React.Component<
               colors={this.state.config.color}
             />
             {this.state.showSidePanel ? (
-              <Media at="large" className="sidePanel">
+              <Media greaterThanOrEqual="large" className="sidePanel">
                 <Tab panes={sidePanelTabs} />
               </Media>
             ) : null}

src/chart.tsx

@@ -429,7 +429,7 @@ function ChartComponent(props: ChartComponentProps) {
 
   return (
     <div id="svgContainer">
-      <Media at="large" className="zoom">
+      <Media greaterThanOrEqual="large" className="zoom">
         <button
           className="zoom-in"
           onClick={() => chartWrapper.current.zoom(ZOOM_FACTOR)}

src/intro.tsx

@@ -128,7 +128,7 @@ export function Intro() {
     <div id="content">
       <div className="backgroundImage" />
       <Card className="intro">
-        <Card.Content as={Media} at="large">
+        <Card.Content as={Media} greaterThanOrEqual="large">
           <Card.Header>
             <FormattedMessage
               id="intro.title"
@@ -137,7 +137,7 @@ export function Intro() {
           </Card.Header>
         </Card.Content>
         <Card.Content>
-          <Grid as={Media} at="large">
+          <Grid as={Media} greaterThanOrEqual="large">
             <Grid.Row>
               <Grid.Column width={5}>
                 <Image src={logo} alt="Topola logo" />

src/menu/top_bar.tsx

@@ -347,7 +347,7 @@ export class TopBar extends React.Component<RouteComponentProps & Props> {
       <>
         <Menu
           as={Media}
-          at="large"
+          greaterThanOrEqual="large"
           attached="top"
           inverted
           color="blue"