make directory redirects absolute paths

I think this is always the right choice, since we're rewriting the full
input path

incorporealcms/pages.py

@@ -27,7 +27,7 @@ def display_page(path):
     except PermissionError:
         abort(400)
     except IsADirectoryError:
-        return redirect(f'{path}/', code=301)
+        return redirect(f'/{path}/', code=301)
     except FileNotFoundError:
         abort(404)
 

incorporealcms/templates/404.html

@@ -10,7 +10,7 @@
 <div class="content">
     <h1>NOT FOUND</h1>
     <p>Sorry, <b><tt>{{ request.path }}</tt></b> does not seem to exist, at least not anymore.</p>
-    <p>It's possible you followed a dead link on this site, in which case I would appreciate it if you could email me via:
+    <p>It's possible you followed a dead link on this site, in which case I would appreciate it if you could email me at
     {{ config.CONTACT_EMAIL }} and I can take a look. I make an effort to symlink old content to its new location,
     so old links and URLs should, generally speaking, work.</p>
     <p>Otherwise, I suggest you go <a href="/">to the index</a> and navigate your way (hopefully) to what