Add 2.8 version (#4240)

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

_config.yml

@@ -5,10 +5,10 @@ baseurl: "/docs/latest" # the subpath of your site, e.g. /blog
 url: "https://opensearch.org" # the base hostname & protocol for your site, e.g. http://example.com
 permalink: /:path/
 
-opensearch_version: '2.7.0'
-opensearch_dashboards_version: '2.7.0'
-opensearch_major_minor_version: '2.7'
-lucene_version: '9_5_0'
+opensearch_version: '2.8.0'
+opensearch_dashboards_version: '2.8.0'
+opensearch_major_minor_version: '2.8'
+lucene_version: '9_6_0'
 
 # Build settings
 markdown: kramdown

_data/versions.json

@@ -1,10 +1,11 @@
 {
-  "current": "2.7",
+  "current": "2.8",
   "all": [
-    "2.7",
+    "2.8",
     "1.3"
   ],
   "archived": [
+    "2.7",
     "2.6",
     "2.5",
     "2.4",
@@ -16,7 +17,7 @@
     "1.1",
     "1.0"
     ],
-  "latest": "2.7"
+  "latest": "2.8"
 }