DOCS/ link to a demo app, docs improvments

Author: JedrzejMaluszczak

README.rst

@@ -23,3 +23,8 @@ Documentation
 http://django-cron.readthedocs.org/en/latest/
 
 This open-source app is brought to you by Tivix, Inc. ( http://tivix.com/ )
+
+Demo App
+=============
+
+https://github.com/Tivix/django-crone-demo

docs/sample_cron_configurations.rst

@@ -64,27 +64,33 @@ Run monthly feature
 --------------------
 ``run_monthly_on_days`` specifies the day of the month on which the job should be run.
 
-You can set your job to run every month at particular day, for example at the 1st and 10th day of month.
+You have to combine ``run_monthly_on_days`` with  ``run_at_times`` or ``run_every_mins``.
+
+You can set your job to run every month at particular day, for example at 6:30 on the 1st and 10th day of month.
 
 .. code-block:: python
 
     class MyCronJob(CronJobBase):
         RUN_MONTHLY_ON_DAYS = [1, 10]
-        schedule = Schedule(run_monthly_on_days=RUN_MONTHLY_ON_DAYS)
+        RUN_AT_TIMES = ['6:30']
+        schedule = Schedule(run_monthly_on_days=RUN_MONTHLY_ON_DAYS, run_at_times=RUN_AT_TIMES)
 
 Run weekly feature
 --------------------
 ``run_weekly_on_days`` specifies the day of the week on which the job should be run.
 
 Days of the week are numbered from 0 to 6 where 0 is Monday and 6 is Sunday.
 
-You can set your job to run every week at particular day, for example at Saturday and Sunday.
+You have to combine ``run_weekly_on_days`` with  ``run_at_times`` or ``run_every_mins``.
+
+You can set your job to run every week at particular day, for example at Saturday and Sunday at 6:30.
 
 .. code-block:: python
 
     class MyCronJob(CronJobBase):
         RUN_WEEKLY_ON_DAYS = [0, 6]
-        schedule = Schedule(run_weekly_on_days=RUN_WEEKLY_ON_DAYS)
+        RUN_AT_TIMES = ['6:30']
+        schedule = Schedule(run_weekly_on_days=RUN_WEEKLY_ON_DAYS, run_at_times=RUN_AT_TIMES)
 
 Allowing parallels runs
 -----------------------