Migrating documentation of the ObjectiveC runtime code to appledoc. (#1867)

Work for #1866 

Migrates all the public class docs over to appledoc format.  While Xcode is fine with blank lines in `///` comments, appledoc (used by cocoadocs) isn't and was leaving a bunch of info off the doc pages.

The generator still needs to be updated to do this also; that will be a follow up CL.

1 files changed, 35 insertions, 28 deletions

diff --git a/objectivec/GPBUnknownField.h b/objectivec/GPBUnknownField.h
index 0f301e47..a135cc20 100644
--- a/objectivec/GPBUnknownField.h
+++ b/objectivec/GPBUnknownField.h
@@ -36,52 +36,59 @@
 @class GPBUnknownFieldSet;
 
 NS_ASSUME_NONNULL_BEGIN
-
-/// Store an unknown field. These are used in conjunction with @c GPBUnknownFieldSet
+/**
+ * Store an unknown field. These are used in conjunction with
+ * GPBUnknownFieldSet.
+ **/
 @interface GPBUnknownField : NSObject<NSCopying>
 
-/// The field number the data is stored under.
+/** The field number the data is stored under. */
 @property(nonatomic, readonly, assign) int32_t number;
 
-/// An array of varint values for this field.
+/** An array of varint values for this field. */
 @property(nonatomic, readonly, strong) GPBUInt64Array *varintList;
 
-/// An array of fixed32 values for this field.
+/** An array of fixed32 values for this field. */
 @property(nonatomic, readonly, strong) GPBUInt32Array *fixed32List;
 
-/// An array of fixed64 values for this field.
+/** An array of fixed64 values for this field. */
 @property(nonatomic, readonly, strong) GPBUInt64Array *fixed64List;
 
-/// An array of data values for this field.
+/** An array of data values for this field. */
 @property(nonatomic, readonly, strong) NSArray<NSData*> *lengthDelimitedList;
 
-/// An array of groups of values for this field.
+/** An array of groups of values for this field. */
 @property(nonatomic, readonly, strong) NSArray<GPBUnknownFieldSet*> *groupList;
 
-
-/// Add a value to the varintList.
-///
-/// @param value The value to add.
+/**
+ * Add a value to the varintList.
+ *
+ * @param value The value to add.
+ **/
 - (void)addVarint:(uint64_t)value;
-
-/// Add a value to the fixed32List.
-///
-/// @param value The value to add.
+/**
+ * Add a value to the fixed32List.
+ *
+ * @param value The value to add.
+ **/
 - (void)addFixed32:(uint32_t)value;
-
-/// Add a value to the fixed64List.
-///
-/// @param value The value to add.
+/**
+ * Add a value to the fixed64List.
+ *
+ * @param value The value to add.
+ **/
 - (void)addFixed64:(uint64_t)value;
-
-/// Add a value to the lengthDelimitedList.
-///
-/// @param value The value to add.
+/**
+ * Add a value to the lengthDelimitedList.
+ *
+ * @param value The value to add.
+ **/
 - (void)addLengthDelimited:(NSData *)value;
-
-/// Add a value to the groupList.
-///
-/// @param value The value to add.
+/**
+ * Add a value to the groupList.
+ *
+ * @param value The value to add.
+ **/
 - (void)addGroup:(GPBUnknownFieldSet *)value;
 
 @end