Add brackets to argname automatically

Updated aux files

spec/usage_spec.lua

@@ -136,7 +136,7 @@ describe("tests related to usage message generation", function()
             :add_help(false)
          parser:argument "inputs"
             :args "1-2"
-            :argname "<input>"
+            :argname "input"
 
          assert.equal(
             [=[Usage: foo <input> [<input>]]=],
@@ -150,7 +150,7 @@ describe("tests related to usage message generation", function()
          parser:option "--pair"
             :args(2)
             :count "*"
-            :argname{"<key>", "<value>"}
+            :argname{"key", "value"}
 
          assert.equal(
             [=[Usage: foo [--pair <key> <value>]]=],