docs: Add Services reference (#1548)

.github/workflows/generate-reference.yml

@@ -0,0 +1,43 @@
+name: Generate References
+on: 
+  push:
+    branches:
+      - 'master'
+    paths:
+      - packages/medusa/src/services/**
+jobs:
+  services:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Cancel Previous Runs
+        uses: styfle/cancel-workflow-action@0.9.1
+        with:
+          access_token: ${{ github.token }}
+
+      - name: Checkout
+        uses: actions/checkout@v2.3.5
+        with:
+          fetch-depth: 0
+
+      - name: Setup Node.js environment
+        uses: actions/setup-node@v2.4.1
+        with:
+          node-version: "14"
+          cache: "yarn"
+        
+      - name: Bootstrap packages
+        uses: ./.github/actions/cache-bootstrap
+        with:
+          extension: unit-tests
+
+      - name: Build Packages
+        run: yarn build
+
+      - name: Generate Services Reference
+        run: yarn generate:services
+
+      - uses: stefanzweifel/git-auto-commit-action@v4
+        with: 
+          commit_message: Automatically Generated Services Reference
+          file_pattern: docs/content/*
+          skip_dirty_check: false