[DOCS] Add 8.1.0 release notes (#1911)

Author: jrodewig

docs/src/reference/asciidoc/appendix/release-notes/8.1.0.adoc

@@ -0,0 +1,35 @@
+[[eshadoop-8.1.0]]
+== Elasticsearch for Apache Hadoop version 8.1.0
+
+coming::[8.1.0]
+
+[[new-8.1.0]]
+[float]
+=== Enhancements
+
+Core::
+- Add support for wildcard fields
+https://github.com/elastic/elasticsearch-hadoop/pull/1823[#1823]
+
+- Add scripted upsert feature
+https://github.com/elastic/elasticsearch-hadoop/pull/1454[#1454]
+
+Spark::
+- Support Scala 2.13 for Apache Spark 3.2.0
+https://github.com/elastic/elasticsearch-hadoop/pull/1841[#1841]
+
+- Add support for update output mode to structured streaming
+https://github.com/elastic/elasticsearch-hadoop/pull/1839[#1839]
+
+[[bug-8.1.0]]
+[float]
+=== Bug fixes
+
+Core::
+- Check result of bulk writes
+https://github.com/elastic/elasticsearch-hadoop/pull/1870[#1870]
+
+Spark::
+- Add support for upserts of nested arrays
+https://github.com/elastic/elasticsearch-hadoop/pull/1838[#1838]
+

docs/src/reference/asciidoc/appendix/release.adoc

@@ -9,6 +9,7 @@ This section summarizes the changes in each release.
 [[release-notes-8]]
 ===== 8.x
 
+* <<eshadoop-8.1.0>>
 * <<eshadoop-8.0.1>>
 * <<eshadoop-8.0.0>>
 * <<eshadoop-8.0.0-rc2>>
@@ -55,6 +56,7 @@ http://github.com/elastic/elasticsearch-hadoop/issues/XXX[#XXX]
 
 ////////////////////////
 
+include::release-notes/8.1.0.adoc[]
 include::release-notes/8.0.1.adoc[]
 include::release-notes/8.0.0.adoc[]
 include::release-notes/8.0.0-rc2.adoc[]