Add proposal form

Closes #6

Form can be prefilled using query params on the route. The params are
`recipient`, `amount`, `url` and `ipfsHash`.

app/styles/app.scss

@@ -65,6 +65,22 @@ section {
       }
     }
   }
+
+  &#proposals-open, &#proposals-closed {
+    .actions {
+      padding-top: 3rem;
+      font-size: 1rem;
+      color: lightblue;
+      text-align: center;
+      @include media($mobile) {
+        padding-top: 2rem;
+      }
+
+      a {
+        color: lightblue;
+      }
+    }
+  }
 }
 
 button, input[type=submit] {

app/styles/components/_add-contributor.scss

@@ -1,4 +1,4 @@
-section#add-contributor {
+section#add-contributor, section#add-proposal {
 
   form {
 
@@ -8,6 +8,10 @@ section#add-contributor {
       &.actions {
         padding-top: 1rem;
         text-align: center;
+        a {
+          color: lightblue;
+          margin-left: 1rem;
+        }
       }
     }