Update splash screen and use light-mode logo for now

web/src/About.svelte

@@ -6,19 +6,45 @@
 {#if $showAbout}
   <Modal on:close={() => ($showAbout = false)} let:dialog>
     <h1>15-minute neighborhood tool</h1>
-    <p>TODO. Extremely early in development.</p>
+    <p>
+      This is an <b>experimental</b> tool to explore how transportation and land-use
+      interacts. From a start point, how far can somebody reach in 15 minutes by
+      walking, cycling, or with public transit? Within that area, what points of
+      interest are around?
+    </p>
+    <p>
+      This is a newer version of an <a
+        href="https://a-b-street.github.io/docs/software/fifteen_min.html"
+        target="_blank">older tool</a
+      >. It's still under development. If you have any questions or ideas about
+      it, please
+      <a href="https://github.com/a-b-street/15m/issues/new" target="_blank"
+        >file an issue</a
+      >
+      or email
+      <a href="mailto:[email protected]">[email protected]</a>.
+    </p>
+    <p>
+      This tool contains data from
+      <a href="https://www.openstreetmap.org/about" target="_blank"
+        >OpenStreetMap</a
+      >, the UK
+      <a href="https://www.bus-data.dft.gov.uk/" target="_blank"
+        >Bus Open Data Service</a
+      >, and census data from several countries using
+      <a
+        href="https://github.com/Urban-Analytics-Technology-Platform/popgetter"
+        target="_blank">popgetter</a
+      >.
+    </p>
     <p>
       This <a href="https://github.com/a-b-street/15m/" target="_blank"
         >open source</a
       >
       tool is created by
       <a href="https://github.com/dabreegster/" target="_blank"
         >Dustin Carlino</a
-      >
-      and relies heavily on
-      <a href="https://www.openstreetmap.org/about" target="_blank"
-        >OpenStreetMap</a
-      > data.
+      >.
     </p>
 
     <center

web/src/App.svelte

@@ -1,7 +1,7 @@
 <script lang="ts">
   import "@picocss/pico/css/pico.jade.min.css";
   import cycleParking from "../assets/bicycle_parking.png?url";
-  import logoDark from "../assets/logo_dark.svg?url";
+  import logo from "../assets/logo_light.svg?url";
   import About from "./About.svelte";
   import { notNull } from "svelte-utils";
   import { Geocoder } from "svelte-utils/map";
@@ -122,7 +122,7 @@
 <Layout>
   <div slot="top" style="display: flex">
     <button class="outline" on:click={() => ($showAbout = true)}>
-      <img src={logoDark} style="height: 6vh;" alt="A/B Street logo" />
+      <img src={logo} style="height: 6vh;" alt="A/B Street logo" />
     </button>
     <span bind:this={topDiv} style="width: 100%" />
   </div>