A tag is required to reuse Elasticsearch breaking changes in the Stack
Guide. To display properly, the breaking changes must use external
links rather than xrefs.
This PR correctly places those tags for reuse. It also replaces
several xrefs with external links for reuse.
Date histogram interval parameter was deprecated in 7.2, in favor of the more specific fixed_interval and calendar_interval parameters. The old logic used some poorly understood guessing to decide if it should operate in fixed or calendar mode. The new logic requires a specific choice by the user, which is more explicit. In 7.x REST compatibility mode, we will parse the interval as calendar if possible, and otherwise interpret it as fixed.
Adds `//tag::notable-breaking-changes[]` to several breaking changes
files. This tag is required for reuse in the [Elastic Stack Installation
and Upgrade Guide][0].
Also replaces a relative xref with an external links. External links are
required for reuse in the Installation and Upgrade Guide.
[0]: https://www.elastic.co/guide/en/elastic-stack/master/index.html
James Rodewig
Mark Tozzi
debadair
James Rodewig
Hendrik Muhs