Update docs, add godoc badge

[ci skip]

README.md

@@ -1,4 +1,4 @@
-# go-face [![Build Status](https://travis-ci.org/Kagami/go-face.svg?branch=master)](https://travis-ci.org/Kagami/go-face)
+# go-face [![Build Status](https://travis-ci.org/Kagami/go-face.svg?branch=master)](https://travis-ci.org/Kagami/go-face) [![GoDoc](https://godoc.org/github.com/Kagami/go-face?status.svg)](https://godoc.org/github.com/Kagami/go-face)
 
 go-face implements face recognition for Go using [dlib](http://dlib.net), a
 popular machine learning toolkit.

error.go

@@ -11,7 +11,7 @@ func (e ImageLoadError) Error() string {
 	return string(e)
 }
 
-// An Serialization is returned when provided model is corrupted.
+// An SerializationError is returned when provided model is corrupted.
 type SerializationError string
 
 func (e SerializationError) Error() string {

face.go

@@ -32,14 +32,16 @@ type Face struct {
 }
 
 // Descriptor holds 128-dimensional feature vector.
-type Descriptor [descrLen]float32
+type Descriptor [128]float32
 
 // New creates new face with the provided parameters.
 func New(r image.Rectangle, d Descriptor) Face {
 	return Face{r, d}
 }
 
-// NewRecognizer returns a new recognizer interface
+// NewRecognizer returns a new recognizer interface. modelDir points to
+// directory with shape_predictor_5_face_landmarks.dat and
+// dlib_face_recognition_resnet_model_v1.dat files.
 func NewRecognizer(modelDir string) (rec *Recognizer, err error) {
 	cModelDir := C.CString(modelDir)
 	defer C.free(unsafe.Pointer(cModelDir))