Document Redis Sentinel settings

[pmclain]

magento-engcom/php-7.2-support#39
magento-engcom/php-7.2-support#1

[vkublytskyi]

Seems this changes should be targeted to guides/v2.3/config-guide/redis/redis-session.md as provided information will not be correct for M2.2.

@pmclain, @buskamuza we need to discuss where to contribute docuemntation regarding changes introduced for PHP 7.2 support. Delivering it directly in guides/v2.3/ may cause an issue if project will not be finished before 2.3.0 release.

[buskamuza]

@vkublytskyi , general rule is to deliver docs together with PRs. So I think it's ok to target 2.3 for now. But some doc PRs may be not merged because corresponding dev PRs are not merged. In this case we should be able to duplicate the doc PRs to a necessary branch later.

This specific one should be OK - the dev PR should be merged to 2.3-develop w/o waiting for all other tasks.

[jeff-matthews]

@buskamuza, it sounds like everyone agrees that this is a 2.3 change, however this PR is modifying the 2.2 version of the file. If we're targeting 2.3, we must update the 2.3 version of the file; not the 2.2 version.

@dshevtsov, please don't merge this PR until we get confirmation.

[buskamuza]

Yes. It should be 2.3.

[jeff-matthews]

@dshevtsov, please make these changes to the guides/v2.3/config-guide/redis/redis-session.md file instead.

You'll need to delete the current guides/v2.3/config-guide/redis/redis-session.md symlink, create a new 2.3 file based on the 2.2 content, and then make these changes.

[dshevtsov]

I created an internal ticket: MAGEDOC-2798

[dshevtsov]

@pmclain I replaced a symlink guides/v2.3/config-guide/redis/redis-session.md with a copy of the guides/v2.2/config-guide/redis/redis-session.md file.

Please update your PR to move your changes to guides/v2.3/config-guide/redis/redis-session.md instead of guides/v2.2/... (according to the above conversation).

[dshevtsov]

@buskamuza is this PR still relevant?

[dshevtsov]

I pulled the changes, moved them to 2.3, and published in a separate commit.