tpl: Add docshelper for template funcs

And fix some other minor related issues.

Updates #3418

tpl/cast/init.go

@@ -24,21 +24,27 @@ func init() {
 	f := func(d *deps.Deps) *internal.TemplateFuncsNamespace {
 		ctx := New()
 
-		examples := [][2]string{
-			{`{{ "1234" | int | printf "%T" }}`, `int`},
-			{`{{ 1234 | string | printf "%T" }}`, `string`},
-		}
-
-		return &internal.TemplateFuncsNamespace{
+		ns := &internal.TemplateFuncsNamespace{
 			Name:    name,
 			Context: func() interface{} { return ctx },
-			Aliases: map[string]interface{}{
-				"int":    ctx.ToInt,
-				"string": ctx.ToString,
-			},
-			Examples: examples,
 		}
 
+		ns.AddMethodMapping(ctx.ToInt,
+			[]string{"int"},
+			[][2]string{
+				{`{{ "1234" | int | printf "%T" }}`, `int`},
+			},
+		)
+
+		ns.AddMethodMapping(ctx.ToString,
+			[]string{"string"},
+			[][2]string{
+				{`{{ 1234 | string | printf "%T" }}`, `string`},
+			},
+		)
+
+		return ns
+
 	}
 
 	internal.AddTemplateFuncsNamespace(f)