Added comments

Author: thivya-amazon

src/app/icd/client/CheckInDelegate.h

@@ -24,6 +24,12 @@ namespace chip {
 namespace app {
 
 /// Callbacks for check in protocol
+/**
+ * @brief The application implementing an ICD client should inherit the CheckInDelegate and implement the listed callbacks
+ * OnCheckInComplete will be called on successful processing of a received checkIn message from the server
+ * OnRefreshKey will be called when the key needs to be refreshed to avoid check in counter roll over problems. On receiving
+ * OnRefreshKey callback, the application should generate a new key.
+ */
 class DLL_EXPORT CheckInDelegate
 {
 public:
@@ -40,7 +46,7 @@ class DLL_EXPORT CheckInDelegate
      * @brief Callback used to let the application know that a checkin message was received and validated and a key refresh is
      * needed to avoid counter roolover problems.
      *
-     * The implementor of this function should generate a new key
+     * The implementer of this function should generate a new key
      *
      * @param[out] keyData - new key generated
      */