Basic onboading flow (#24)

* removed unused file

* [WIP] Created onboarding form

* Finished basic onboarding flow; added tests

* Improved onboarding language

lib/pinchflat_web/components/layouts/partials/header.html.heex

@@ -7,7 +7,7 @@
       >
         <.icon name="hero-bars-3" />
       </button>
-      <a class="hidden sm:block flex-shrink-0 lg:hidden" href="#">
+      <a class="hidden sm:block flex-shrink-0 lg:hidden" href="/">
         <h2 class="text-title-md2 font-bold text-white">Pinchflat</h2>
       </a>
     </div>
@@ -22,7 +22,7 @@
             name="q"
             value={@params["q"]}
             placeholder="Type to search..."
-            class="w-full bg-transparent pl-9 pr-4 border-0 focus:ring-0 focus:outline-none xl:w-125"
+            class="w-full bg-transparent pl-9 pr-4 border-0 focus:ring-0 focus:outline-none lg:w-125"
           />
         </form>
       </div>