add headers to axios get request code example

Example 1: headers in axios.get

const axios = require('axios');

// httpbin.org gives you the headers in the response
// body `res.data`.
// See: https://httpbin.org/#/HTTP_Methods/get_get
const res = await axios.get('https://httpbin.org/get', {
  headers: {
    'Test-Header': 'test-value'
  }
});

res.data.headers['Test-Header']; // "test-value"

Example 2: axios set request header

header("Access-Control-Allow-Origin: *");   
header("Access-Control-Allow-Methods: GET, POST, OPTIONS, HEAD");
header("Access-Control-Allow-Headers: Content-Type, header1");