message: Limit remove-diff-signs to diff tables
  and not in any nested code view
diff: @@ -3,7 +3,7 @@ import select from 'select-dom';
  import observeEl from '../libs/simplified-element-observer';
  function removeDiffSigns() {
  - for (const line of select.all('.diff-table tr:not(.refined-github-diff-signs)')) {
  + for (const line of select.all('.diff-table > tbody > tr:not(.refined-github-diff-signs)')) {
  line.classList.add('refined-github-diff-signs');
  for (const code of select.all('.blob-code-inner', line)) {
  // Drop -, + or space
  