message: Simplify `hide-readme-header`: Fixes "Jump to definition" bug
diff: -/* Hide the header in README section */
  -.repository-content #readme:not(.blob) {
  - position: relative;
  +.repository-content #readme:not(.blob) .Box-title {
  + visibility: hidden;
  }
  .repository-content #readme:not(.blob) .Box-header {
  - position: absolute;
  - top: 0;
  - right: 0;
  - background-color: transparent !important;
  - padding: 0 !important;
  - border: none;
  -}
  -
  -.repository-content #readme:not(.blob) .Box-header .Box-title {
  - display: none;
  + margin-bottom: -40px;
  }
  .repository-content #readme:not(.blob) .Box-header .btn-octicon {
  - margin: 0;
  - padding: 12px;
  - right: 0;
  - top: 0;
  - opacity: 20%;
  transition: opacity 0.25s;
  }
  -.repository-content #readme:not(.blob) .Box-header .btn-octicon:hover,
  -.repository-content #readme:not(.blob) .Box-header .btn-octicon:focus {
  - opacity: 100%;
  -}
  -
  -/* Restore spacing #3495 */
  -.repository-content #readme:not(.blob) .Box-body {
  - padding-top: 32px;
  +.repository-content #readme:not(.blob) .Box-header .btn-octicon:not(:hover, :focus) {
  + opacity: 20%;
  }
  