Add routing and pages for managing templates

So that users can see what it the flow is like to:
- add new templates
- edit existing templates

app/templates/components/submit-form.html

@@ -1,11 +1,9 @@
-{% macro submit_form(button_text, back_link) %}
+{% macro submit_form(button_text, back_link=False) %}
   <div class="submit-form">
-    <form method="POST" enctype="multipart/form-data">
-      <input type="hidden" name="csrf_token" value="{{ csrf_token() }}" />
-      <input type="submit" class="button" value="{{ button_text }}" />
-      {% if back_link %}
-        <a class="submit-form-back-link" role="button" href="{{ back_link }}">Back</a>
-      {% endif %}
-    </form>
+    <input type="hidden" name="csrf_token" value="{{ csrf_token() }}" />
+    <input type="submit" class="button" value="{{ button_text }}" />
+    {% if back_link %}
+      <a class="submit-form-back-link" role="button" href="{{ back_link }}">Back</a>
+    {% endif %}
   </div>
 {% endmacro %}

app/templates/components/textbox.html

@@ -0,0 +1,10 @@
+{% macro textbox(name, label, value='', small=True) %}
+  <div class="form-group">
+    <label class="form-label" for="{{ name }}">{{ label }}</label>
+    {% if small %}
+      <input class="form-control" id="{{ name }}" name="{{ name }}" type="text" value="{{ value }}">
+    {% else %}
+      <textarea class="form-control" id="{{ name }}" name="{{ name }}" cols="30" rows="10">{{ value }}</textarea>
+    {% endif %}
+  </div>
+{% endmacro %}