Short doc for crc function

src/crc64.h

@@ -6,4 +6,9 @@
 
 #include <stdint.h>
 
+
+/**
+ * @brief Generates and returns a 64-bit Cyclic Redundancy Check from a
+ *        character string s of length l.
+ */
 uint64_t crc64(const char* s, uint64_t l);