Support for custom html meta (#1423)

* Support for custom html meta

* Changed html meta description default

modules/templates/helper.go

@@ -110,6 +110,15 @@ func NewFuncMap() []template.FuncMap {
 		"ThemeColorMetaTag": func() string {
 			return setting.UI.ThemeColorMetaTag
 		},
+		"MetaAuthor": func() string {
+			return setting.UI.Meta.Author
+		},
+		"MetaDescription": func() string {
+			return setting.UI.Meta.Description
+		},
+		"MetaKeywords": func() string {
+			return setting.UI.Meta.Keywords
+		},
 		"FilenameIsImage": func(filename string) bool {
 			mimeType := mime.TypeByExtension(filepath.Ext(filename))
 			return strings.HasPrefix(mimeType, "image/")