[DOCS] Add maintenance releases to upgrade table (#55012)

Updates the supported upgrade path table in [Upgrade Elasticsearch][0]
to include a new row for maintenance releases. For example, this row
covers upgrading from 7.6.0 to 7.6.2.

The new table row only displays for releases greater than n.x.0. For
example, the new row will display for the 7.7.1 release but not the
7.7.0 release.

[0]: https://www.elastic.co/guide/en/elasticsearch/reference/master/setup-upgrade.html

docs/reference/upgrade.asciidoc

@@ -10,14 +10,22 @@ process so upgrading does not interrupt service. Rolling upgrades are supported:
 * From 5.6 to 6.8
 * From 6.8 to {prev-major-version}
 * From {prev-major-version} to {version}
+ifeval::[ "{version}" != "{minor-version}.0" ]
+* From any version since {minor-version}.0 to {version}
+endif::[]
 
 
 The following table shows the recommended upgrade paths to {version}.
 
-[cols="<1m,3",options="header",]
+[cols="<1,3",options="header",]
 |====
 |Upgrade from   
-|Recommended upgrade path  to {version}
+|Recommended upgrade path to {version}
+
+ifeval::[ "{version}" != "{minor-version}.0" ]
+|A previous {minor-version} version (e.g., {minor-version}.0)
+|<<rolling-upgrades,Rolling upgrade>> to {version}
+endif::[]
 
 |{prev-major-version}
 |<<rolling-upgrades,Rolling upgrade>> to {version}

docs/reference/upgrade/rolling_upgrade.asciidoc

@@ -35,6 +35,9 @@ Rolling upgrades are supported:
 * {stack-ref-68}/upgrading-elastic-stack.html[From 5.6 to 6.8]
 * {stack-ref-70}/upgrading-elastic-stack.html[From 6.8 to 7.0]
 * From {prev-major-version} to {version}
+ifeval::[ "{version}" != "{minor-version}.0" ]
+* From any version since {minor-version}.0 to {version}
+endif::[]
 
 Upgrading directly to {version} from 6.6 or earlier requires a
 <<restart-upgrade, full cluster restart>>.