feat: add app code

- journal domain package
- httpserver package
- html templates
- main.go in root dir

httpserver/renderer.go

@@ -0,0 +1,39 @@
+package httpserver
+
+import (
+	"fmt"
+	"html/template"
+	"io/fs"
+	"log"
+	"net/http"
+)
+
+type TemplateRenderer struct {
+	templatesFS fs.FS
+}
+
+func NewTemplateRenderer(templatesFS fs.FS) *TemplateRenderer {
+	return &TemplateRenderer{
+		templatesFS: templatesFS,
+	}
+}
+
+func (r *TemplateRenderer) Render(w http.ResponseWriter, templatePath string, data interface{}) {
+	tmpl, err := template.ParseFS(r.templatesFS, fmt.Sprintf("templates/%s", templatePath), "templates/layout.html")
+	if err != nil {
+		InternalServerError(w, nil)
+		log.Printf("failed to parse template %s: %v", templatePath, err)
+
+		return
+	}
+
+	err = tmpl.Execute(w, data)
+	if err != nil {
+		InternalServerError(w, nil)
+		log.Printf("failed to execute template %s: %v", templatePath, err)
+
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+}