Addresses part of #16, (#71)

Integrate gatsby-plugin-intl for internationalization
Replaces static text with `intl.formatMessage` call and Links with `gatsby-plugin-intl` equivalent
Note: `npm install` now requires `--force` to install the latest `gatsby-plugin-intl` as it doesn't explicitly support gatsby3.0

client/src/components/J40footer.tsx

@@ -1,6 +1,6 @@
 import React from 'react';
 import { Footer } from '@trussworks/react-uswds';
-import {Link} from 'gatsby';
+import {Link} from 'gatsby-plugin-intl';
 
 const footerLinks = [
     <Link to="/">Home</Link>

client/src/components/J40header.tsx

@@ -1,17 +1,21 @@
 import React from 'react';
 import { GovBanner, Header, Title, PrimaryNav } from '@trussworks/react-uswds';
-import { Link } from "gatsby";
+import { useIntl, Link } from "gatsby-plugin-intl"
 
 const headerLinks = [
     <Link to="/">Home</Link>
 ];
 
 const J40Header = () => {
+    const intl = useIntl()
+    const title = intl.formatMessage({ id: "71L0pp", defaultMessage:"Justice40", description:"Title of the project" });
     return (
         <>
         <GovBanner />
         <Header>
-            <Title>Justice 40</Title>
+            <Title>
+                {title}
+            </Title>
             <PrimaryNav items={headerLinks}/>
         </Header>
         </>

client/src/intl/en.json

@@ -0,0 +1,6 @@
+{
+  "71L0pp": {
+    "defaultMessage": "Justice40",
+    "description": "Title of the project"
+  }
+}

client/src/intl/es.json

@@ -0,0 +1,3 @@
+{
+  "71L0pp": "Justicia40"
+}

client/src/pages/404.tsx

@@ -1,5 +1,5 @@
-import * as React from "react"
-import { Link } from "gatsby"
+import * as React from "react";
+import { Link } from "gatsby-plugin-intl";
 
 // styles
 const pageStyles = {

client/src/pages/index.tsx

@@ -1,11 +1,15 @@
 import * as React from "react"
 import Layout from '../components/layout';
-
 // markup
-export default function IndexPage() {
+const IndexPage = () => {
+  
   return (
-      <Layout>
-        <title>Justice40</title>
-      </Layout>
+    <Layout>
+      <main>
+        <h2>Subheader</h2>
+      </main>
+    </Layout>
   )
-}
+}
+
+export default IndexPage;