Final improvements

README.md

@@ -148,32 +148,6 @@ var args struct {
 arg.MustParse(&args)
 ```
 
-### Custom placeholders
-
-```go
-var args struct {
-	Input    string   `arg:"positional" placeholder:"SRC"`
-	Output   []string `arg:"positional" placeholder:"DST"`
-	Optimize int      `arg:"-O" help:"optimization level" placeholder:"LEVEL"`
-	MaxJobs  int      `arg:"-j" help:"maximum number of simultaneous jobs" placeholder:"N"`
-}
-arg.MustParse(&args)
-```
-```shell
-$ ./example -h
-Usage: example [--optimize LEVEL] [--maxjobs N] SRC [DST [DST ...]]
-
-Positional arguments:
-  SRC
-  DST
-
-Options:
-  --optimize LEVEL, -O LEVEL
-                         optimization level
-  --maxjobs N, -j N      maximum number of simultaneous jobs
-  --help, -h             display this help and exit
-```
-
 ### Default values (before v1.2)
 
 ```go
@@ -361,6 +335,34 @@ $ ./example
 main.NameDotName{Head:"file", Tail:"txt"}
 ```
 
+### Custom placeholders
+
+Use the `placeholder` tag to control which placeholder text is used in the usage text.
+
+```go
+var args struct {
+	Input    string   `arg:"positional" placeholder:"SRC"`
+	Output   []string `arg:"positional" placeholder:"DST"`
+	Optimize int      `arg:"-O" help:"optimization level" placeholder:"LEVEL"`
+	MaxJobs  int      `arg:"-j" help:"maximum number of simultaneous jobs" placeholder:"N"`
+}
+arg.MustParse(&args)
+```
+```shell
+$ ./example -h
+Usage: example [--optimize LEVEL] [--maxjobs N] SRC [DST [DST ...]]
+
+Positional arguments:
+  SRC
+  DST
+
+Options:
+  --optimize LEVEL, -O LEVEL
+                         optimization level
+  --maxjobs N, -j N      maximum number of simultaneous jobs
+  --help, -h             display this help and exit
+```
+
 ### Description strings
 
 ```go

example_test.go

@@ -136,7 +136,7 @@ func Example_helpText() {
 }
 
 // This example shows the usage string generated by go-arg with customized placeholders
-func Example_helpDataname() {
+func Example_helpPlaceholder() {
 	// These are the args you would pass in on the command line
 	os.Args = split("./example --help")