Add context documentation

Author: cmanallen

develop-docs/sdk/data-model/event-payloads/contexts.mdx

@@ -832,3 +832,37 @@ The required field is `package` which should contain the package or framework wh
   }
 }
 ```
+
+## Feature Flag Context
+
+The feature flag context contains information about the flags evaluated prior to an error occurring. Flag evaluation results are placed into the `values` key which is an array of 0 or more flag evaluation result objects.
+
+`flag`
+
+: **Required.** The name of the flag which was evaluated.
+
+- Example: `"feature-is-enabled"`
+
+`result`
+
+: **Required.** The boolean result of flag evaluation.
+
+- Example: `false`
+
+
+### Example Featuer Flag Context
+
+```json
+{
+  "contexts": {
+    "flags": {
+      "values": [
+        {
+          "flag": "my_flag_name",
+          "result": true
+        }
+      ]
+    }
+  }
+}
+```