Basic onboading flow (#24)

* removed unused file

* [WIP] Created onboarding form

* Finished basic onboarding flow; added tests

* Improved onboarding language

lib/pinchflat_web/controllers/pages/page_html/home.html.heex

@@ -0,0 +1,8 @@
+<div class="rounded-sm border border-stroke bg-white shadow-default dark:border-strokedark dark:bg-boxdark">
+  <div class="max-w-full overflow-x-auto">
+    <div class="flex flex-col gap-10 text-center my-10">
+      <h2 class="text-2xl">TODO: Put some useful info or analytics here</h2>
+      <p>For now, the options in the sidebar have what you need</p>
+    </div>
+  </div>
+</div>