Improve readability of setup step (solidcouch#118)

- Add styling to distinguish setup steps better
- Improve description of data storage options
- Add form and native validation of inputs

It's still not beautiful and user friendly, but at least it's more
readable, and the options for data storage are explained.

Also there's a form now, and it prevents submitting invalid data.

src/pages/HospexSetup/HospexSetup.module.scss

@@ -0,0 +1,16 @@
+.taskList {
+  li {
+    margin: 1rem;
+    list-style-type: disc;
+    border-left: 4px solid black;
+    padding-left: 0.5rem;
+  }
+
+  .storageOptions {
+    margin-left: 1rem;
+    .option {
+      margin: 0.5rem;
+      margin-left: 1rem;
+    }
+  }
+}