<sa> - Small <a>s

sa.js

// <sa> - small <a>

const dictionary = {
  'congruent': '#definition-of-congruent',

  'right angle': '#definition-of-right-angle',
  'right angles': '#definition-of-right-angle',

  'definition of supplementary': '#definition-of-supplementary',
  'congruent supplementary angles': '#congruent-supplementary-angles'
}

for (let sa of document.querySelectorAll('sa')) {
  const text = sa.textContent.toLowerCase()
  const a = document.createElement('a')
  if (dictionary.hasOwnProperty(text)) {
    a.href = dictionary[text]
  }
  a.textContent = sa.textContent
  sa.parentNode.insertBefore(a, sa)
  sa.remove()
}