Escapes HTML characters and JavaScript line terminators
Adapted from serialize-javascript.
The use case of this module is to safely embed content into a <script> element within an HTML document.
const safeString = require('safe-string');
const string = JSON.stringify({foo: '</script>'});
// => '{"foo":"</script>"}'
const escaped = safeString(string);
// => '{"foo":"\u003C\u002Fscript\u003E"}'
const html = `<script type="application/json">${escaped}</script>`;
// => '<script type="application/json">{"foo":"\u003C\u002Fscript\u003E"}</script>'
const parsed = JSON.parse(escaped);
// => {foo: '</script>'}