Add warning message about 8.x versions

[mgreau]

This commit adds a warning message to the README to
notify users that the role will be deprecated.

[elasticdog]

👍

[jsermer]

why is this ansible role being abandoned for 8.x+?

[nkammah]

@jsermer We’ve discussed it internally and have decided to officially stop development of the ansible-elasticsearch and ansible-beats module once 8.X is released.

[wixaw]

Hummm , and now how can we easily keep our infrastructure up to date?

[nkammah]

I would recommend looking at other community maintained roles or explore migrating to our cloud managed offering.

[wixaw]

ok thanks

[jsermer]

so do you also plan on dropping support for puppet and chef...they're all three linked in your docs:

https://www.elastic.co/guide/en/elasticsearch/reference/current/install-elasticsearch.html#config-mgmt-tools

[nkammah]

Our puppet modules have been handed over to Vox Pupuli (see voxpupuli/puppet-logstash#403) , as for the Chef cookbooks, they are not actively maintained. I'll make sure the above doc page get updated appropriately.

[raf64flo]

What about mentioning the Terraform provider as an alternative in this readme, in order to promote the new way of provisioning ES stack?