docs: document customized header (#396)

doc/examples/template.md

@@ -0,0 +1,16 @@
+# Customizing the submission script header
+
+When submitting jobs to some clusters, such as the [Tiger Cluster](https://researchcomputing.princeton.edu/systems/tiger) at Princeton University, the Slurm header is quite different from the standard one. In this case, DPDispatcher allows users to customize the templates by setting {dargs:argument}`strategy/customized_script_header_template_file <resources/strategy/customized_script_header_template_file>` to a template file:
+
+```{literalinclude} ../../examples/resources/tiger.json
+:language: json
+:linenos:
+```
+
+`template.slurm` is the template file, where {meth}`str.format` is used to format the template with [Resources Parameters](resources):
+
+```{literalinclude} ../../examples/resources/template.slurm
+:linenos:
+```
+
+See [Python Format String Syntax](https://docs.python.org/3/library/string.html#formatstrings) for how to insert parameters inside the template.

doc/index.rst

@@ -29,7 +29,10 @@ DPDispatcher will monitor (poke) until these jobs finish and download the result
    :caption: Examples
    :glob:
 
-   examples/*
+   examples/expanse
+   examples/g16
+   examples/shell
+   examples/template
 
 .. toctree::
    :caption: Project details