feat: implement example and README (#3)

* fix: go module name

* feat: implement example usage

* feat: write README

Author: pranc1ngpegasus

README.md

@@ -1 +1,17 @@
-# golang-template
+# middlechain
+
+The simple HTTP middleware chainer for Golang.
+
+## How to use
+
+```go
+mux := http.NewServeMux()
+
+handler := middlechain.Chain(mux,
+  someMiddleware,
+)
+
+// handle http request...
+
+http.ListenAndServe(":8080", handler)
+```

_example/example.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/Pranc1ngPegasus/middlechain"
+)
+
+func main() {
+	mux := http.NewServeMux()
+
+	handler := middlechain.Chain(mux,
+		heaatbeat("/ping"),
+	)
+
+	if err := http.ListenAndServe(":8080", handler); err != nil {
+		panic(err)
+	}
+}
+
+func heaatbeat(endpoint string) func(h http.Handler) http.Handler {
+	return func(h http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if (r.Method == http.MethodGet || r.Method == http.MethodHead) && strings.EqualFold(r.URL.Path, endpoint) {
+				w.Header().Set("Content-Type", "text/plain")
+				w.WriteHeader(http.StatusOK)
+				w.Write([]byte("."))
+
+				return
+			}
+		})
+	}
+}

go.mod

@@ -1,4 +1,4 @@
-module github.com/Pranc1ngPegasus/golang-template
+module github.com/Pranc1ngPegasus/middlechain
 
 go 1.19