Adding bundle build action (#222)

Tested with forked repo and private test bundle

Author: Michael Lacore

README.md

@@ -145,7 +145,7 @@ Deploys a configured application to Massdriver.
 
 ```yaml
 jobs:
-  publish:
+  deploy:
     runs-on: ubuntu-latest
     env:
       MASSDRIVER_API_KEY: ${{ secrets.MASSDRIVER_API_KEY }}
@@ -162,14 +162,13 @@ jobs:
           manifest: db
 ```
 
-
 ### App Patch
 
 This action will patch the parameters of an existing application.
 
 ```yaml
 jobs:
-  publish:
+  patch:
     runs-on: ubuntu-latest
     env:
       MASSDRIVER_API_KEY: ${{ secrets.MASSDRIVER_API_KEY }}
@@ -208,13 +207,32 @@ jobs:
         uses: massdriver-cloud/actions/bundle_publish@v4
 ```
 
+### Bundle Build
+
+Use this action to build schemas from massdriver.yaml:
+
+```yaml
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    env:
+      MASSDRIVER_API_KEY: ${{ secrets.MASSDRIVER_API_KEY }}
+      MASSDRIVER_ORG_ID: ${{ vars.MASSDRIVER_ORG_ID }}
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install Massdriver CLI
+        uses: massdriver-cloud/actions@v4
+      - name: Build Bundle
+        uses: massdriver-cloud/actions/bundle_build@v4
+```
+
 ### Image Push
 
 Use this action to push an image, using the Massdriver CLI, to any of the supported cloud providers.
 
 ```yaml
 jobs:
-  publish:
+  image_push:
     runs-on: ubuntu-latest
     env:
       MASSDRIVER_API_KEY: ${{ secrets.MASSDRIVER_API_KEY }}

bundle_build/action.yml

@@ -0,0 +1,12 @@
+name: 'Build Bundle'
+description: 'Builds schemas from massdriver.yaml file'
+author: 'Massdriver, Inc.'
+inputs:
+  build-directory:
+    description: |
+      Path to a directory containing a massdriver.yaml file.
+    required: false
+    default: '.'
+runs:
+  using: node20
+  main: '../dist/bundle_build/index.js'