add documentation

README.md

@@ -21,12 +21,16 @@ It supports:
 
 ## Usage
 
+### Content Negotiation
+
+With the `Type` function you can negotiate the content type of HTTP request.
+
 ```go
 package main
 
 import (
 	"net/http"
-	"gitlab.schukai.com/oss/libraries/go/application/http-negotiation"
+	"gitlab.schukai.com/oss/libraries/go/network/http-negotiation"
 )
 
 func handleRequest(w http.ResponseWriter, r *http.Request) {
@@ -42,6 +46,75 @@ func handleRequest(w http.ResponseWriter, r *http.Request) {
 
 ```
 
+### Language Negotiation
+
+With the `Language` function you can negotiate the language of HTTP request.
+
+```go
+package main
+
+import (
+	"net/http"
+	"gitlab.schukai.com/oss/libraries/go/network/http-negotiation"
+)
+
+func handleRequest(w http.ResponseWriter, r *http.Request) {
+	n := negotiation.New(r.Header)
+
+	if n.Language("en-GB", "en") != "en" {
+		// ...
+	}
+
+}
+
+```
+
+### Charset Negotiation
+
+With the `Charset` function you can negotiate the charset of HTTP request.
+
+```go
+package main
+
+import (
+	"net/http"
+	"gitlab.schukai.com/oss/libraries/go/network/http-negotiation"
+)
+
+func handleRequest(w http.ResponseWriter, r *http.Request) {
+	n := negotiation.New(r.Header)
+
+	if n.Charset("utf-8", "iso-8859-1") != "utf-8" {
+		// ...
+	}
+
+}
+
+```
+
+### Encoding Negotiation
+
+With the `Encoding` function you can negotiate the encoding of HTTP request.
+
+```go
+package main
+
+import (
+	"net/http"
+	"gitlab.schukai.com/oss/libraries/go/network/http-negotiation"
+)
+
+func handleRequest(w http.ResponseWriter, r *http.Request) {
+	n := negotiation.New(r.Header)
+
+	if n.Encoding("gzip", "deflate") != "gzip" {
+		// ...
+	}
+
+}
+
+```
+
 ## Contributing
 
 Merge requests are welcome. For major changes, please open an issue first to discuss what