added section about master key config (#667)

* added section about master key config

* Update _includes/cloudcode/cloud-code-advanced.md

Co-Authored-By: Tom Fox <[email protected]>

* updated field wording according to dashboard

* added section about master key config

* Update _includes/cloudcode/cloud-code-advanced.md

Co-Authored-By: Tom Fox <[email protected]>

* updated field wording according to dashboard

* added internal config docs

Author: mtrezza

_includes/cloudcode/cloud-code-advanced.md

@@ -569,3 +569,13 @@ Here's an example of the JSON data that would be sent in the request to this web
 ```
 
 After setting up your webhook in the Dashboard UI, you'll be acurately decrementing comment counts!
+
+# Config
+Parse Config offers a convenient way to configure parameters in Cloud Code.
+
+```javascript
+const config = await Parse.Config.get({useMasterKey: true});
+const privateParam = config.get("privateParam");
+```
+
+By default, Parse Config parameters can be publicly read which may be undesired if the parameter contains sensitive information that should not be exposed to clients. A parameter can be made readable only with the master key by setting the `Requires master key?` property via the Parse Dashboard to `Yes`.

_includes/js/config.md

@@ -55,6 +55,22 @@ Parse.Config.get().then(function(config) {
 });
 ```
 
+## Internal Config
+
+By default, Parse Config parameters can be publicly read which may be undesired if the parameter contains sensitive information that should not be exposed to clients. A parameter can be saved as readable only with the master key by adding a flag as the second argument.
+
+```javascript
+await Parse.Config.save(
+  { welcomeMessage : "Welcome to Parse", secretMessage: "Psst 👀" },
+  { secretMessage: true }
+);
+
+const publicConfig = await Parse.Config.get(); // Returns only `welcomeMessage`.
+const internalConfig = await Parse.Config.get({ useMasterKey: true }); // Returns `welcomeMessage` and `secretMessage`.
+```
+
+If a parameter is not provided or set to `false` in the second argument, it can be retrieved without using the master key.
+
 ## Current Config
 
 Every `Parse.Config` instance that you get is always immutable. When you retrieve a new `Parse.Config` in the future from the network, it will not modify any existing `Parse.Config` instance, but will instead create a new one and make it available via `Parse.Config.current()`. Therefore, you can safely pass around any `current()` object and safely assume that it will not automatically change.