Wording improvements in the zero_authorized_projects template

I've reworded the first sentence to say "You don't have access to any projects",
which I think sounds more natural.

I've also used the "pluralize" ActionView helper for the user's projects_limit,
so that it still looks good when it says "You can create up to 1 project.".

Finally, I've tweaked the structure of the final sentence a little bit to make
it sound a bit better.

app/views/dashboard/_zero_authorized_projects.html.haml

 %h3.nothing_here_message
-  There are no projects you have access to.
+  You don't have access to any projects.
   %br
   - if current_user.can_create_project?
     You can create up to
-    = current_user.projects_limit
-    projects. Click on button below to add a new one
+    = pluralize(current_user.projects_limit, "project") + "."
+    Click on the button below to add a new one
     .link_holder
       = link_to new_project_path, class: "btn btn-primary" do
         New Project »
   - else
-    If you will be added to project - it will be displayed here
+    If you are added to a project, it will be displayed here