main usage: fix GCC 15 warning

fix the warning:
```
/usr/include/c++/15.2.1/bits/new_allocator.h:172:66: warning: ‘void operator delete(void*, std::size_t)’ called on pointer ‘__result’ with nonzero offset 32 [-Wfree-nonheap-object]
  172 |         _GLIBCXX_OPERATOR_DELETE(_GLIBCXX_SIZED_DEALLOC(__p, __n));
```

full warning:
<https://gist.github.com/MartinPulec/976f020990831e40de4dc206f2cebf30>

Most likely false positive.

Author: MartinPulec

src/main.cpp

@@ -72,6 +72,7 @@
 #include <cstring>                      // for strcmp, strlen, strtok_r, strchr
 #include <exception>                    // for exception
 #include <getopt.h>
+#include <initializer_list>             // for initializer_list
 #include <iostream>
 #include <map>                          // for map
 #include <memory>
@@ -199,7 +200,9 @@ static void signal_handler(int signum)
         exit_uv(0);
 }
 
-static void print_help_item(const string &name, const vector<string> &help) {
+static void
+print_help_item(const string &name, initializer_list<string> help)
+{
         int help_lines = 0;
 
         col() << "\t" << TBOLD(<< name <<);