Why std::initializer_list cannot move?

Question

P(std::initializer_list<Tag> children) : Tag("p", std::move(children)) {}
clang tidy warns as follows.

error: std::move of the variable 'children' of the trivially-copyable type std::initializer_list<Tag> has no effect; remove std::move() [hicpp-move-const-arg,performance-move-const-arg,-warnings-as-errors] P(std::initializer_list<Tag> children) : Tag("p", std::move(children)) {}

Is the reason why std::initializer_list cannot move because it is an array?
I looked up the definition of trivially-copyable, but I'm not sure.

#include <iostream>
#include <string>
#include <vector>

namespace html {
struct Tag
{
  std::string name;
  std::string text;
  std::vector<Tag> children;
  std::vector<std::pair<std::string, std::string>> attributes;

  friend std::ostream &operator<<(std::ostream &os, const Tag &tag)
  {
    os << "<" << tag.name;

    for (const auto &att : tag.attributes) os << " " << att.first << "=\"" << att.second << "\"";

    if (tag.children.size() == 0 && tag.text.length() == 0) {
      os << "/>" << std::endl;
    } else {
      os << ">" << std::endl;

      if (tag.text.length()) { os << tag.text << std::endl; }

      for (const auto &child : tag.children) { os << child; }

      os << "</" << tag.name << ">" << std::endl;
    }

    return os;
  }

protected:
  Tag(std::string name, std::string text) : name{ std::move(name) }, text{ std::move(text) } {}
  Tag(std::string name, std::vector<Tag> children) : name{ std::move(name) }, children{ std::move(children) } {}
};

struct P : Tag
{
  explicit P(std::string text) : Tag{ "p", std::move(text) } {}

  P(std::initializer_list<Tag> children) : Tag("p", std::move(children)) {}
};

struct IMG : Tag
{
  explicit IMG(std::string url) : Tag{ "img", "" } { attributes.emplace_back(make_pair("src", std::move(url))); }
};
}// namespace html

int main1()
{
  using namespace html;

  std::cout <<

    P{ IMG{ "http://pokemon.com/pikachu.png" } }

            << std::endl;

  getchar();
  return 0;
}