Improve release script old version doc

[djhi]

Problem

This is an unnecessary manual step.

Solution

Automate it

How To Test

These scripts support a RELEASE_DRY_RUN env variable allowing to skip all mutations to git, GitHub or npm, except 1 git commit (but not pushed!) from lerna.

First, create a .env file from the .env.template file and fill it in with your Github token.

Then run:

RELEASE_DRY_RUN=true make release

Select the new minor version when Lerna asks for it.

When this is done, don't forget to revert the commit created by lerna to update the versions:

git reset --hard HEAD~1

Additional Checks

• The PR targets master for a bugfix or a documentation fix, or next for a feature