feat(xtemplate): init package, Template interface

New package focused on improving text/template and html/template std
packages.

xtemplate/xtemplate.go

@@ -0,0 +1,31 @@
+package xtemplate
+
+import (
+	"io"
+	"io/fs"
+	"text/template/parse"
+)
+
+type Template interface {
+	AddParseTree(name string, tree *parse.Tree) (Template, error)
+	Clone() (Template, error)
+	DefinedTemplates() string
+	Delims(left, right string) Template
+	Funcs(funcMap template.FuncMap) Template
+	Lookup(name string) Template
+	Name() string
+	New(name string) Template
+	Option(opt ...string) Template
+	Parse(text string) (Template, error)
+	ParseFS(fs fs.FS, patterns ...string) (Template, error)
+	ParseFiles(filenames ...string) (Template, error)
+	ParseGlob(pattern string) (Template, error)
+	Templates() []Template
+
+	Templater
+}
+
+type Templater interface {
+	Execute(wr io.Writer, data any) error
+	ExecuteTemplate(wr io.Writer, name string, data any) error
+}