Remove instructions to change version in README

Author: marthacryan

Diff for: release.md

@@ -29,8 +29,6 @@ Manually update the versions to `X.Y.Z` in the files specified below.
 
  - `CHANGELOG.md`
    + update the release date
- - `README.md`
-   + this must be done at this point because the README gets baked into PyPI
  - `packages/python/plotly/plotly/_widget_version.py`:
    + Update `__frontend_version__` to `^X.Y.Z` (Note the `^` prefix)
  - Commit your changes on the branch: