Chore: add footnote component

components/common/Asterisk.js

@@ -0,0 +1,16 @@
+import React from 'react'
+import { StyleSheet } from 'react-native'
+
+import AppText from './app-text'
+
+import { Colors } from '../../styles'
+
+const Asterisk = () => <AppText style={styles.asterisk}>*</AppText>
+
+const styles = StyleSheet.create({
+  asterisk: {
+    color: Colors.orange,
+  },
+})
+
+export default Asterisk