steps missing from devcontainer setup

[zachariahcox]

we basically need the following commands added as an on-create script (or added to the docker file, etc):

create a file with executable permissions 755
call that file from the "onCreateCommand" hook.

file should contain:

bundle install
yarn install
bin/rails db:setup

In my branch it looks like this:

diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index b0a9069..76ece07 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -31,5 +31,8 @@
        "remoteUser": "vscode",
        "features": {
                "git": "os-provided"
-       }
+       },
+       
+       // Runs automatically after Prebuild Template environment is created.
+       "onCreateCommand": ".devcontainer/on-create-command.sh"
 }
diff --git a/.devcontainer/on-create-command.sh b/.devcontainer/on-create-command.sh
new file mode 100755
index 0000000..269e24c
--- /dev/null
+++ b/.devcontainer/on-create-command.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+set -e
+
+bundle install
+yarn install
+bin/rails db:setup
\ No newline at end of file