Install script should allow passing only major.minor as a version parameter about website

[Haroenv]

The install file is here: https://github.com/yarnpkg/website/blob/master/install.sh

[mgolebiowski]

The easiest way would be to resolve the version using npm, something like

npm view yarn@$1 version | tail -n1 | grep -o "'.*'" | cut -d "'" -f2

Here you can check how the npm solution could look like: mgolebiowski@b8d64d5

If we don't want to use npm, we could follow yarn set version that is using GitHub API[0], this would require parsing the JSON output as well as finding the correct tag to generate the URL.

[0] https://github.com/yarnpkg/yarn/blob/3119382885ea373d3c13d6a846de743eca8c914b/src/cli/commands/policies.js#L52-L55