[DOCS] Adds placeholders for version-specific upgrade steps #234
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Related to #226
This PR moves the existing "Upgrading from 5.6" content to a separate file and creates placeholders for equivalent pages for 6.x- and 7.x-specific instructions.
It also switches the Installation and Upgrade Guide to pulling its version information from the shared versions files, so that it can use the new "prev-major-version" attribute in elastic/docs#675.