message: Fix inconsistent Node version in readme
diff: * Yarn >= 1.7.0\*\*
  * Python 2.7.X\*\*\*
  -<sub>\*Higher versions should work fine, but may cause inconsistencies. It's suggested you run 8.9.4 using `nvm`.</sub>
  +<sub>\*Higher versions should work fine, but may cause inconsistencies. It's suggested you run 8.16.0 using `nvm`.</sub>
  <br/>
  <sub>**npm is NOT supported for package management. MyCrypto uses yarn.lock to ensure sub-dependency versions are pinned, so yarn is required to install node_modules</sub>
  <br/>
  