feat: implemented strcpy, used constant

kernel/libc/libc.c

@@ -14,6 +14,10 @@ int memcpy(char *dst, char *src, int amount) {
     return 0;
 }
 
+int strcpy(char *dst, char *src) {
+    return memcpy(dst, src, strlen(src) + 1);
+}
+
 int memset(char *dst, char data, int amount) {
     for (int i = 0; i < amount; ++i) {
         dst[i] = data;