LibC: Add POSIX spec comments for sched APIs

Userland/Libraries/LibC/sched.cpp

@@ -10,28 +10,33 @@
 
 extern "C" {
 
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_yield.html
 int sched_yield()
 {
     int rc = syscall(SC_yield);
     __RETURN_WITH_ERRNO(rc, rc, -1);
 }
 
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_get_priority_min.html
 int sched_get_priority_min([[maybe_unused]] int policy)
 {
     return 0; // Idle
 }
 
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_get_priority_max.html
 int sched_get_priority_max([[maybe_unused]] int policy)
 {
     return 3; // High
 }
 
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_setparam.html
 int sched_setparam(pid_t pid, const struct sched_param* param)
 {
     int rc = syscall(SC_sched_setparam, pid, param);
     __RETURN_WITH_ERRNO(rc, rc, -1);
 }
 
+// https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_getparam.html
 int sched_getparam(pid_t pid, struct sched_param* param)
 {
     int rc = syscall(SC_sched_getparam, pid, param);