Add onboarding component

src/screens/Onboarding/index.tsx

@@ -0,0 +1,76 @@
+import React, { useCallback, useEffect } from 'react';
+import styled from 'styled-components/native';
+import { THEME_COLOR } from 'CONSTANTS';
+import { Button } from 'react-native';
+import { useNavigation } from '@react-navigation/native';
+import { NavigationProp } from 'screens';
+import { useTypedSelector } from 'store';
+import { useDispatch } from 'react-redux';
+import { setOnboardingStatus } from 'store/settings/actions';
+
+const Container = styled.SafeAreaView`
+    background-color: ${THEME_COLOR};
+    flex: 1;
+    justify-content: center;
+`;
+
+const TextContainer = styled.ScrollView`
+    padding: 25px;
+`;
+
+const Text = styled.Text`
+    text-align: center;
+    color: white;
+    margin-bottom: 10px;
+`;
+
+const ButtonContainer = styled.View`
+    margin-top: 50px;
+`; 
+
+const Logo = styled.Image`
+    width: 150px;
+    height: 150px;
+    margin: 0 auto 50px auto;
+`;
+
+function Onboarding() {
+    // Get account from Redux and dispatcher
+    const account = useTypedSelector(state => state.settings.jellyfin);
+    const dispatch = useDispatch();
+
+    // Also retrieve the navigation handler so that we can open the modal in
+    // which the Jellyfin server is set
+    const navigation = useNavigation<NavigationProp>();
+    const handleClick = useCallback(() => navigation.navigate('SetJellyfinServer'), [navigation]);
+    
+    // We'll also respond to any change in the account, setting the onboarding
+    // status to true, so that the app becomes available.
+    useEffect(() => {
+        if (account) {
+            dispatch(setOnboardingStatus(true));
+        }
+    }, [account, dispatch]);
+    
+    return (
+        <Container>
+            <TextContainer contentContainerStyle={{ flexGrow: 1, justifyContent: 'center' }}>
+                <Logo source={require('../../assets/app-icon-white.png')} />
+                <Text >
+                    Welcome!
+                </Text>
+                <Text>
+                    Jellyfin Audio Player will allow you to stream your music library from anywhere, with full support for background audio and casting. 
+                </Text>
+                <Text>
+                    In order to get started, you need a Jellyfin server. Click the button below to enter your Jellyfin server address and login to it.
+                </Text>
+                <ButtonContainer>
+                    <Button title="Set Jellyfin Server" color="#ffffff" onPress={handleClick} />
+                </ButtonContainer>
+            </TextContainer>
+        </Container>
+    );
+}
+
+export default Onboarding;