function functionEntry (name) {
    const fn = functions[name]
    let syntax = SYNTAX[name] || (fn.doc && fn.doc.syntax && fn.doc.syntax[0]) || name
    syntax = syntax
      // .replace(/^math\./, '')
      .replace(/\s+\/\/.*$/, '')
      .replace(/;$/, '')
    if (syntax.length < 40) {
      syntax = syntax.replace(/ /g, '&nbsp;')
    }

    let description = ''
    if (fn.doc.description) {
      description = fn.doc.description.replace(/\n/g, ' ').split('.')[0] + '.'
    }

    return '[' + syntax + '](functions/' + name + '.md) | ' + description
  }
Helper function to generate a markdown list entry for a function.
Used to generate both alphabetical and categorical index pages.
@param {string} name Function name
@returns {string}    Returns a markdown list entry