added alt attributes to img tags in starter projects component and when using this component on ev3 page

src/components/extension-landing/project-card.jsx

@@ -8,7 +8,10 @@ const ProjectCard = props => (
         href={props.cardUrl}
     >
         <div className="project-card-image">
-            <img src={props.imageSrc} />
+            <img
+                alt={props.imageAlt}
+                src={props.imageSrc}
+            />
         </div>
         <div className="project-card-info">
             <h4>{props.title}</h4>
@@ -20,6 +23,7 @@ const ProjectCard = props => (
 ProjectCard.propTypes = {
     cardUrl: PropTypes.string,
     description: PropTypes.string,
+    imageAlt: PropTypes.string,
     imageSrc: PropTypes.string,
     title: PropTypes.string
 };

src/views/ev3/ev3.jsx

@@ -210,18 +210,21 @@ class EV3 extends ExtensionLanding {
                         <ProjectCard
                             cardUrl="https://downloads.scratch.mit.edu/ev3/ev3-wave-hello.sb3"
                             description={this.props.intl.formatMessage({id: 'ev3.waveHelloDescription'})}
+                            imageAlt={this.props.intl.formatMessage({id: 'ev3.imgAltWaveHello'})}
                             imageSrc="/images/ev3/starter-wave-hello.png"
                             title={this.props.intl.formatMessage({id: 'ev3.waveHelloTitle'})}
                         />
                         <ProjectCard
                             cardUrl="https://downloads.scratch.mit.edu/ev3/ev3-distance-instrument.sb3"
                             description={this.props.intl.formatMessage({id: 'ev3.distanceInstrumentDescription'})}
+                            imageAlt={this.props.intl.formatMessage({id: 'ev3.imgAltDistanceInstrument'})}
                             imageSrc="/images/ev3/starter-distance-instrument.png"
                             title={this.props.intl.formatMessage({id: 'ev3.distanceInstrumentTitle'})}
                         />
                         <ProjectCard
                             cardUrl="https://downloads.scratch.mit.edu/ev3/ev3-space-tacos.sb3"
                             description={this.props.intl.formatMessage({id: 'ev3.spaceTacosDescription'})}
+                            imageAlt={this.props.intl.formatMessage({id: 'ev3.imgAltSpaceTacos'})}
                             imageSrc="/images/ev3/starter-flying-game.png"
                             title={this.props.intl.formatMessage({id: 'ev3.spaceTacosTitle'})}
                         />

src/views/ev3/l10n.json

@@ -41,5 +41,8 @@
     "ev3.imgAltAcceptPasscode": "Use the center button of your EV3 to accept the passcode.",
     "ev3.imgAltWaitForWindows": "Windows notifies you when EV3 is ready.",
     "ev3.imgAltEnterPasscodeMac": "Enter the passcode into the connection request window opening on your Mac.",
-    "ev3.imgAltPlugInMotor": "Port A is not to be confused with Port 4 on the other side of the EV3."
+    "ev3.imgAltPlugInMotor": "Port A is not to be confused with Port 4 on the other side of the EV3.",
+    "ev3.imgAltWaveHello": "A fairy",
+    "ev3.imgAltDistanceInstrument": "A guitar on stage",
+    "ev3.imgAltSpaceTacos": "A cat and a taco in space"
 }