README.md improved

README.md

@@ -83,4 +83,77 @@ func doStuffWrapped() error {
 fmt.Println(adverr.Trace())
 ```
 
-### 
+### Example of a printed error
+Code:
+```go
+package main
+
+import (
+	"adverr"
+	"errors"
+)
+
+var (
+	ErrDoStuffFailed = adverr.NewErrTmpl("ErrDoStuffFailed", "Could'nt do stuff because of %s")
+)
+
+func main() {
+	err := doStuffInAnotherGoroutine()
+	if err != nil {
+		adverr.Fatalln(err, 1)
+	}
+}
+
+func doStuff() error {
+	err := doGoNativeStuff()
+	if err != nil {
+		return ErrDoStuffFailed.Wrap(err, "reasons")
+	}
+
+	return nil
+}
+
+func doStuffInAnotherGoroutine() error {
+	ch := make(chan error, 1)
+
+	go func() {
+		ch <- doStuff()
+		close(ch)
+	}()
+
+	err := <-ch
+	if err != nil {
+		return adverr.Wrap("Goroutine failed because of errors", err)
+	}
+
+	return nil
+}
+
+func doGoNativeStuff() error {
+	return errors.New("some go error")
+}
+
+```
+Output:
+```
+adverr.Error: Goroutine failed because of errors
+        at main.doStuffInAnotherGoroutine (/home/user/go/src/test/main.go:38)
+        at main.main (/home/user/go/src/test/main.go:13)
+        at runtime.main (/usr/local/go/src/runtime/proc.go:204)
+Caused by ErrDoStuffFailed: Could'nt do stuff because of reasons
+        at main.doStuff (/home/user/go/src/test/main.go:22)
+        at main.doStuffInAnotherGoroutine.func1 (/home/user/go/src/test/main.go:32)
+Caused by errors.errorString: some go error
+        (Unknown source)
+```
+
+### Globals
+You can set the maximum limit of the call stack trace via
+```go
+adverr.CallStackLength = 50 // default value: 100
+```
+
+If you are in a productive environment, consider disabling call traces completely for performance reasons:
+```go
+adverr.DisableTrace = true // default value: false
+```