chore: add some annotations (#1544)

ref: #1075 
because I am not a native English, maybe have a bit problem.

render/html.go

@@ -9,20 +9,27 @@ import (
 	"net/http"
 )
 
+// Delims represents a set of Left and Right delimiters for HTML template rendering.
 type Delims struct {
-	Left  string
+	// Left delimiter, defaults to {{.
+	Left string
+	// Right delimiter, defaults to }}.
 	Right string
 }
 
+// HTMLRender interface is to be implemented by HTMLProduction and HTMLDebug.
 type HTMLRender interface {
+	// Instance returns an HTML instance.
 	Instance(string, interface{}) Render
 }
 
+// HTMLProduction contains template reference and its delims.
 type HTMLProduction struct {
 	Template *template.Template
 	Delims   Delims
 }
 
+// HTMLDebug contains template delims and pattern and function with file list.
 type HTMLDebug struct {
 	Files   []string
 	Glob    string
@@ -30,6 +37,7 @@ type HTMLDebug struct {
 	FuncMap template.FuncMap
 }
 
+// HTML contains template reference and its name with given interface object.
 type HTML struct {
 	Template *template.Template
 	Name     string
@@ -38,6 +46,7 @@ type HTML struct {
 
 var htmlContentType = []string{"text/html; charset=utf-8"}
 
+// Instance (HTMLProduction) returns an HTML instance which it realizes Render interface..
 func (r HTMLProduction) Instance(name string, data interface{}) Render {
 	return HTML{
 		Template: r.Template,
@@ -46,6 +55,7 @@ func (r HTMLProduction) Instance(name string, data interface{}) Render {
 	}
 }
 
+// Instance (HTMLDebug) returns an HTML instance which it realizes Render interface..
 func (r HTMLDebug) Instance(name string, data interface{}) Render {
 	return HTML{
 		Template: r.loadTemplate(),
@@ -66,6 +76,7 @@ func (r HTMLDebug) loadTemplate() *template.Template {
 	panic("the HTML debug render was created without files or glob pattern")
 }
 
+// Render (HTML) executes template and writes its result with custom ContentType for response.
 func (r HTML) Render(w http.ResponseWriter) error {
 	r.WriteContentType(w)
 
@@ -75,6 +86,7 @@ func (r HTML) Render(w http.ResponseWriter) error {
 	return r.Template.ExecuteTemplate(w, r.Name, r.Data)
 }
 
+// WriteContentType (HTML) writes HTML ContentType.
 func (r HTML) WriteContentType(w http.ResponseWriter) {
 	writeContentType(w, htmlContentType)
 }