Rename Plugin.Render to Plugin.Inject

This function doesn't render anything, it just adds extra data to the
template data.

plugin.go

@@ -10,6 +10,6 @@ type Plugin interface {
 	Name() string
 	Filters() template.FuncMap
 	SetRoutes(group *echo.Group)
-	Render(name string, data interface{}) error
+	Inject(name string, data interface{}) error
 	Close() error
 }

plugin_lua.go

@@ -68,7 +68,7 @@ func (p *luaPlugin) setRoute(l *lua.LState) int {
 	return 0
 }
 
-func (p *luaPlugin) Render(name string, data interface{}) error {
+func (p *luaPlugin) Inject(name string, data interface{}) error {
 	f, ok := p.renderCallbacks[name]
 	if !ok {
 		return nil

template.go

@@ -19,7 +19,7 @@ func (t *tmpl) Render(w io.Writer, name string, data interface{}, ectx echo.Cont
 	ctx := ectx.Get("context").(*context)
 
 	for _, plugin := range ctx.server.plugins {
-		if err := plugin.Render(name, data); err != nil {
+		if err := plugin.Inject(name, data); err != nil {
 			return fmt.Errorf("failed to run plugin '%v': %v", plugin.Name(), err)
 		}
 	}