Make arguments param optional; update README

This commit makes the arguments parameter optional by adding a default
value for it. It also updates the README to be clearer about how to
write tailored taskplans, and updates the test plan to use return()
instead of notice().

README.md

@@ -18,7 +18,13 @@ bolt task run taskplan \
 
 ### Plan-specific tailored taskplan task
 
-To create a plan-specific tailored taskplan task, use something like the following:
+The task `taskplan` is generic, and can run any plan, but because it permits the user to pass arbitrary command line flags to Bolt, it is effectively a privileged task.
+
+As an alternative to permitting users to run the generic privileged task, a plan-specific tailored task, built on taskplan, can be created. 
+
+To create a tailored plan-specific taskplan, use the following pattern.
+
+tailored.json file:
 
 ```json
 {
@@ -40,6 +46,8 @@ To create a plan-specific tailored taskplan task, use something like the followi
 }
 ```
 
+tailored.rb file:
+
 ```ruby
 #!/opt/puppetlabs/puppet/bin/ruby
 require 'json'

plans/test.pp

@@ -2,6 +2,6 @@
   String $message,
 ) {
 
-  notice("Ran taskplan::test! Message: ${message}")
+  return("Ran taskplan::test! Message: ${message}")
 
 }

tasks/init.json

@@ -1,17 +1,18 @@
 {
-  "description": "Run a Puppet task plan with Bolt",
+  "description": "A task to run a Puppet plan with Bolt",
   "parameters": {
     "plan": {
       "type": "String[1]",
-      "description": "The task plan to run"
+      "description": "The plan to run"
     },
     "params": {
       "type": "Hash",
-      "description": "Parameters to give to the task plan"
+      "description": "Parameters to give to the plan"
     },
     "arguments": {
       "type": "Hash",
-      "description": "Hash of Bolt arguments to pass, e.g.: {modulepath=>/expl/path, ssl-verify=>false}"
+      "description": "Hash of Bolt arguments to pass, e.g.: {modulepath=>/expl/path, ssl-verify=>false}",
+      "default": { }
     },
     "debug": {
       "type": "Optional[Boolean]",