feat: add nbb.core await example

Per babashka/nbb#258 (comment)

readme.org

@@ -60,20 +60,33 @@ Loaded module
 Loaded main.cljs
 
 
-$> nbb src/main-imp-del-async.cljs
+$> nbb src/main-imp-async.cljs
 ;; Fails: Imperative delayed async import
 Loaded main.cljs
 Cannot find module '/Users/aisamu/code/node/nbb-relative-async-imports/src/helper.mjs'
 Require stack:
-- /Users/aisamu/code/node/nbb-relative-async-imports/src/main-imp-del-async.cljs
+- /Users/aisamu/code/node/nbb-relative-async-imports/src/main-imp-async.cljs
 
 
-$> nbb src/main-imp-async.cljs
+$> nbb src/main-imp-del-async.cljs
 ;; Fails: Imperative delayed async import
 Loaded main.cljs
 Cannot find module '/Users/aisamu/code/node/nbb-relative-async-imports/src/helper.mjs'
 Require stack:
-- /Users/aisamu/code/node/nbb-relative-async-imports/src/main-imp-async.cljs
+- /Users/aisamu/code/node/nbb-relative-async-imports/src/main-imp-del-async.cljs
+
+
+$> nbb src/main-imp-async-awaited.cljs
+;; Works: Imperative do-delayed async import awaited
+Loaded helper.mjs
+Loaded module
+Loaded main.cljs
+
+
+$> nbb src/main-imp-del-async-awaited.cljs
+;; Half-works: Imperative promise-delayed async import awaited
+Loaded helper.mjs
+Loaded module
 #+end_src
 
 #+begin_quote

src/main-imp-async-awaited.cljs

@@ -0,0 +1,10 @@
+;; Works: Imperative do-delayed async import awaited
+(ns main
+  (:require [promesa.core :as p]
+            [nbb.core :refer [await]]))
+
+;; It tries to load helper.mjs from '/src/helper.mjs'
+;;                       instead of '/src/modules/module/helper.mjs'
+(await (p/do (require '[modules.module.core])))
+
+(println "Loaded main.cljs")

src/main-imp-del-async-awaited.cljs

@@ -0,0 +1,10 @@
+;; Half-works: Imperative promise-delayed async import awaited
+(ns main
+  (:require [promesa.core :as p]
+            [nbb.core :refer [await]]))
+
+(await (js/Promise. #(require '[modules.module.core])))
+
+;; Never gets executed
+(println "Loaded main.cljs")
+(js/console.log "js: Loaded main.cljs")