message: simplify firstCharacter
diff: setup.firstCharacter = (word) => {
  /** @param word */
  - const character = word.slice(0, 1).toUpperFirst()
  - const restOfWord = word.slice(1)
  - return `<span class="firstcharacter">${character}</span>${restOfWord}`
  - // return `<span class="firstcharacter">${word.slice(0, 1)}</span>${word.slice(1)}`
  + return `<span class="firstcharacter">${word.slice(0, 1)}</span>${word.slice(1)}`
  }
  