Document readme.md serious error about the options of delimiters

[donaldtone]

options.delimiters
Type: String
Default: ---

Open and close delimiters can be passed in as an array of strings.

Example:

// format delims as a string
matter.read('file.md', {delims: '~~~'});
// or an array (open/close)
matter.read('file.md', {delims: ['~~~', '~~~']});

the example is wrong.
it should use delimiters instead of delims.

like that:

Example:

// format delims as a string
matter.read('file.md', {delimiters: '~~~'});
// or an array (open/close)
matter.read('file.md', {delimiters: ['~~~', '~~~']});

[eikowagenknecht]

I checked the code. Indeed delims is still the primary source and delimiters is only used when delims is not present.

  // ensure that delimiters are an array
  opts.delimiters = utils.arrayify(opts.delims || opts.delimiters || '---');
  if (opts.delimiters.length === 1) {
    opts.delimiters.push(opts.delimiters[0]);
  }