Fix GitHub checkout action configuration to pull submodules

..blooper introduced in the latest commit where submodules were to be
pulled to make sure mustache spec tests were included in test runs.

.github/workflows/verify.yml

@@ -12,7 +12,8 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-        submodules: recursive
+        with:
+          submodules: recursive
       - name: Setup Node.js
         uses: actions/setup-node@v1
         with:
@@ -31,7 +32,8 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-        submodules: recursive
+        with:
+          submodules: recursive
       - name: Setup Node.js
         uses: actions/setup-node@v1
         with: