add missing keywords (#244)

* add missing keywords

* add missing keywords

Author: patricklx

src/main/kotlin/com/emberjs/hbs/Internals.kt

@@ -41,6 +41,7 @@ object Internals {
             "query-params",
             "textarea",
             "unbound",
+            "readonly",
             "unless",
             "yield",
             "has-block-params",
@@ -58,4 +59,4 @@ object Internals {
             "TextArea" to listOf("@ember/component", "component"),
             "LinkTo" to listOf("@ember/routing", "component"),
     )
-}
+}