Remove the changelog (#30593)

We are starting over on the changelog with a different approach. This
commit removes the existing incarnation of the changelog to remove
confusion that we need to continue adding entries to it.

docs/CHANGELOG.asciidoc

@@ -1,257 +0,0 @@
-[[es-release-notes]]
-= {es} Release Notes
-
-[partintro]
---
-// To add a release, copy and paste the template text
-// and add a link to the new section. Note that release subheads must
-// be floated and sections cannot be empty.
-
-// Use these for links to issue and pulls. Note issues and pulls redirect one to
-// each other on Github, so don't worry too much on using the right prefix.
-:issue: https://github.com/elastic/elasticsearch/issues/
-:pull: https://github.com/elastic/elasticsearch/pull/
-
-This section summarizes the changes in each release.
-
-* <<release-notes-7.0.0>>
-* <<release-notes-6.4.0>>
-* <<release-notes-6.3.1>>
-
---
-
-////
-// To add a release, copy and paste the following text,  uncomment the relevant
-// sections, and add a link to the new section in the list of releases at the
-// top of the page. Note that release subheads must be floated and sections
-// cannot be empty.
-// TEMPLATE:
-
-// [[release-notes-n.n.n]]
-// == {es} n.n.n
-
-//[float]
-[[breaking-n.n.n]]
-//=== Breaking Changes
-
-//[float]
-//=== Breaking Java Changes
-
-//[float]
-//=== Deprecations
-
-//[float]
-//=== New Features
-
-//[float]
-//=== Enhancements
-
-//[float]
-//=== Bug Fixes
-
-//[float]
-//=== Regressions
-
-//[float]
-//=== Known Issues
-
-////
-
-[[release-notes-7.0.0]]
-== {es} 7.0.0
-
-coming[7.0.0]
-
-[float]
-[[breaking-7.0.0]]
-=== Breaking Changes
-
-<<write-thread-pool-fallback, Removed `thread_pool.bulk.*` settings and
-`es.thread_pool.write.use_bulk_as_display_name` system property>> ({pull}29609[#29609])
-
-<<systemd-service-file-config, Systemd service file is no longer marked as configuration>> ({pull}29004[#29004])
-<<remove-suggest-metric, Removed `suggest` metric on stats APIs>> ({pull}29635[#29635])
-
-<<remove-field-caps-body, In field capabilities APIs, removed support for providing fields in the request body>> ({pull}30185[#30185])
-
-Machine Learning::
-* The `max_running_jobs` node property is removed in this release. Use the
-`xpack.ml.max_open_jobs` setting instead. For more information, see <<ml-settings>>.
-
-* <<remove-http-enabled, Removed `http.enabled` setting>> ({pull}29601[#29601])
-
-//[float]
-//=== Breaking Java Changes
-
-[float]
-=== Deprecations
-Monitoring::
-* The `xpack.monitoring.collection.interval` setting can no longer be set to `-1`
-to disable monitoring data collection. Use `xpack.monitoring.collection.enabled`
-and set it to `false` (its default), which was added in 6.3.0.
-
-Security::
-* The fields returned as part of the mappings section by get index, get
-mappings, get field mappings, and field capabilities API are now only the
-ones that the user is authorized to access in case field level security is enabled.
-
-//[float]
-//=== New Features
-
-//[float]
-//=== Enhancements
-
-[float]
-=== Bug Fixes
-
-Use date format in `date_range` mapping before fallback to default ({pull}29310[#29310])
-
-Fix NPE in 'more_like_this' when field has zero tokens ({pull}30365[#30365])
-
-Fixed prerelease version of elasticsearch in the `deb` package to sort before GA versions
-({pull}29000[#29000])
-
-Rollup::
-* Validate timezone in range queries to ensure they match the selected job when
-searching ({pull}30338[#30338])
-
-SQL::
-* Fix parsing of Dates containing milliseconds ({pull}30419[#30419])
-
-[float]
-=== Regressions
-Fail snapshot operations early when creating or deleting a snapshot on a repository that has been
-written to by an older Elasticsearch after writing to it with a newer Elasticsearch version. ({pull}30140[#30140])
-
-Fix NPE when CumulativeSum agg encounters null value/empty bucket ({pull}29641[#29641])
-Do not fail snapshot when deleting a missing snapshotted file ({pull}30332[#30332])
-
-//[float]
-//=== Regressions
-
-//[float]
-//=== Known Issues
-
-[[release-notes-6.4.0]]
-== {es} 6.4.0
-
-coming[6.4.0]
-
-//[float]
-[[breaking-6.4.0]]
-//=== Breaking Changes
-
-//[float]
-//=== Breaking Java Changes
-
-[float]
-=== Deprecations
-
-Deprecated multi-argument versions of the request methods in the RestClient.
-Prefer the "Request" object flavored methods. ({pull}30315[#30315])
-
-[float]
-=== New Features
-
-The new <<mapping-ignored-field,`_ignored`>> field allows to know which fields
-got ignored at index time because of the <<ignore-malformed,`ignore_malformed`>>
-option. ({pull}30140[#29658])
-
-A new analysis plugin called `analysis_nori` that exposes the Lucene Korean
-analysis module.  ({pull}30397[#30397])
-
-[float]
-=== Enhancements
-
-{ref-64}/breaking_64_api_changes.html#copy-source-settings-on-resize[Allow
-copying source settings on index resize operations] ({pull}30255[#30255], {pull}30404[#30404])
-
-Added new "Request" object flavored request methods in the RestClient. Prefer
-these instead of the multi-argument versions. ({pull}29623[#29623])
-
-Added `setJsonEntity` to `Request` object so it is marginally easier to send JSON. ({pull}30447[#30447])
-Watcher HTTP client used in watches now allows more parallel connections to the
-same endpoint and evicts long running connections. ({pull}30130[#30130])
-
-The cluster state listener to decide if watcher should be
-stopped/started/paused now runs far less code in an executor but is more
-synchronous and predictable. Also the trigger engine thread is only started on
-data nodes. And the Execute Watch API can be triggered regardless is watcher is
-started or stopped. ({pull}30118[#30118])
-
-Added put index template API to the high level rest client ({pull}30400[#30400])
-
-Add ability to filter coordinating-only nodes when interacting with cluster
-APIs. ({pull}30313[#30313])
-
-[float]
-=== Bug Fixes
-
-Use date format in `date_range` mapping before fallback to default ({pull}29310[#29310])
-
-Fix NPE in 'more_like_this' when field has zero tokens ({pull}30365[#30365])
-
-Do not ignore request analysis/similarity settings on index resize operations when the source index already contains such settings ({pull}30216[#30216])
-
-Fix NPE when CumulativeSum agg encounters null value/empty bucket ({pull}29641[#29641])
-
-Machine Learning::
-
-* Account for gaps in data counts after job is reopened ({pull}30294[#30294])
-
-Add validation that geohashes are not empty and don't contain unsupported characters ({pull}30376[#30376])
-
-Rollup::
-* Validate timezone in range queries to ensure they match the selected job when
-searching ({pull}30338[#30338])
-
-SQL::
-* Fix parsing of Dates containing milliseconds ({pull}30419[#30419])
-
-Allocation::
-
-Auto-expand replicas when adding or removing nodes to prevent shard copies from
-being dropped and resynced when a data node rejoins the cluster ({pull}30423[#30423])
-
-//[float]
-//=== Regressions
-
-//[float]
-//=== Known Issues
-
-[[release-notes-6.3.1]]
-== Elasticsearch version 6.3.1
-
-coming[6.3.1]
-
-//[float]
-[[breaking-6.3.1]]
-//=== Breaking Changes
-
-//[float]
-//=== Breaking Java Changes
-
-//[float]
-//=== Deprecations
-
-//[float]
-//=== New Features
-
-//[float]
-//=== Enhancements
-
-[float]
-=== Bug Fixes
-
-Reduce the number of object allocations made by {security} when resolving the indices and aliases for a request ({pull}30180[#30180])
-
-Respect accept header on requests with no handler ({pull}30383[#30383])
-
-SQL::
-* Fix parsing of Dates containing milliseconds ({pull}30419[#30419])
-
-//[float]
-//=== Regressions
-
-//[float]
-//=== Known Issues