Update readme

README.md

@@ -17,13 +17,46 @@ Then, you can run Snakemake with
 	snakemake --profile slurm ...
 
 
+### Submission scripts
+
+There are two submission scripts that configure jobs for job
+submission. `slurm-submit.py`, the default, will use the supplied
+parameters untouched, making no attempt to modify the job submission
+to comply with the cluster partition configuration. On the other hand,
+`slurm-submit-advanced.py` will attempt to modify memory, time and
+number of tasks if these exceed the limits specified by the slurm
+configuration. If possible, the number of tasks will be increased if
+the requested memory is larger than the available memory, defined as
+the requested number of tasks times memory per cpu unit.
+
 ### Resources
 
 The following resources are supported by on a per-rule basis:
 
-- **mem**: set the memory resource request in mb.
+- **mem**, **mem_mb**: set the memory resource request in mb.
 - **walltime**, **runtime**: set the time resource in min.
 
+### Cluster configuration file
+
+As of 2018-10-08, the profile supports setting options in the cluster
+configuration file. The options must be named according to [sbatch
+long option names](https://slurm.schedmd.com/sbatch.html). Note that
+setting memory or time will override resources specified by rules.
+Therefore, setting time or memory in the `__default__` section will
+effectively override all resource specifications that set these
+parameters.
+
+As an example, you can specify constraints in the cluster
+configuration file:
+
+```yaml
+__default__:
+  constraint: mem500MB
+
+large_memory_requirement_job:
+  constraint: mem2000MB
+```
+
 
 ## Tests
 
@@ -41,3 +74,14 @@ Cookiecutters](https://github.com/hackebrot/pytest-cookies). You can
 run the tests by issuing
 
 	pytest -v -s
+
+
+## ChangeLog
+
+### 2018-10-09
+
+- add support for mem_mb in resources
+- add support for cluster configuration file
+- add advanced slurm-submit file
+- adjust resource requirements if they exceed partition configuration
+  settings (#11)