fix UTF8 combining diaeresis

fixCombiningDiaeresis.js

//https://www.fileformat.info/info/unicode/char/0308/index.htm
//https://vi.stackexchange.com/questions/3557/can-i-search-for-a-unicode-combining-character-in-vim

const fs = require('fs')

const path = __dirname+'/article.md'
const buffer = fs.readFileSync(path)

const fixed = buffer.toString('utf8')
  .replace(/a\u0308/g, 'ä')
  .replace(/u\u0308/g, 'ü')
  .replace(/o\u0308/g, 'ö')

fs.writeFileSync(path+'-new', fixed)