SubGhz: refactoring add descriptions (#1012)

* SubGhz: add descriptions
* SubGhz: fix syntax

Co-authored-by: あく <alleteam@gmail.com>

lib/subghz/blocks/decoder.h

@@ -13,5 +13,16 @@ struct SubGhzBlockDecoder {
     uint8_t decode_count_bit;
 };
 
+/**
+ * Add data bit when decoding.
+ * @param decoder Pointer to a SubGhzBlockDecoder instance
+ * @param bit data, 1bit
+ */
 void subghz_protocol_blocks_add_bit(SubGhzBlockDecoder* decoder, uint8_t bit);
+
+/**
+ * Getting the hash sum of the last randomly received parcel.
+ * @param decoder Pointer to a SubGhzBlockDecoder instance
+ * @return hash Hash sum
+ */
 uint8_t subghz_protocol_blocks_get_hash_data(SubGhzBlockDecoder* decoder, size_t len);