chore: move screens into routes folder

src/routes/Welcome.js

@@ -0,0 +1,61 @@
+import React, { Component } from "react"
+import { Link } from "gatsby"
+import styled from "@emotion/styled"
+import { withTheme } from "emotion-theming"
+
+import { Button, P } from "components/elements"
+import Logo from "components/Logo"
+import { todayUrl } from "utils/date"
+
+const WelcomeGrid = styled.div`
+  margin-top: 30px;
+  line-height: 1.5;
+  color: ${props => props.theme.colors.primary};
+  height: 100%;
+`
+const Footer = styled.footer`
+  margin-top: 120px;
+  padding: 30px 0px;
+  text-align: center;
+  color: ${props => props.theme.colors.secondary};
+`
+const FooterLink = styled(Link)`
+  cursor: pointer;
+  color: ${props => props.theme.colors.secondary};
+  text-decoration: none;
+  margin: 10px;
+  &:hover {
+    color: ${props => props.theme.colors.tertiary};
+  }
+`
+
+class Welcome extends Component {
+  render() {
+    const { theme } = this.props
+    return (
+      <WelcomeGrid>
+        <h1>Your Space for Wandering Thoughts and Ideas</h1>
+        <P style={{ letterSpacing: 1.1, marginBottom: 30 }}>
+          This your space for wandering thoughts and ideas. Write about whatever
+          comes to mind.
+        </P>
+        <Link to={`/app${todayUrl()}`} style={{ textDecoration: "none" }}>
+          <Button colors={theme.colors}>Write about today</Button>
+        </Link>
+        <Footer>
+          <div>
+            <Logo color={theme.colors.logo} />
+          </div>
+          <div>
+            <FooterLink>View on GitHub</FooterLink>
+            <FooterLink to="terms">Terms of Service</FooterLink>
+            <FooterLink to="privacy">Privacy Policy</FooterLink>
+          </div>
+          <div>&copy; 2019</div>
+        </Footer>
+      </WelcomeGrid>
+    )
+  }
+}
+
+export default withTheme(Welcome)