Add main branch to elasticsearch-ruby repo to docs build (#2198)

Author: szabosteve

conf.yaml

@@ -298,13 +298,14 @@ contents:
                 repo:   elasticsearch-ruby
                 path:   docs/examples/guide
                 exclude_branches:   [ 7.x, 7.15, 7.14, 7.13, 7.12, 7.11, 7.10, 7.9, 7.8, 7.7, 7.6, 7.5, 7.4, 7.3, 7.2, 7.1, 7.0, 6.8, 6.7, 6.6, 6.5, 6.4, 6.3, 6.2, 6.1, 6.0, 5.6, 5.5, 5.4, 5.3, 5.2, 5.1, 5.0, 2.4, 2.3, 2.2, 2.1, 2.0, 1.7, 1.6, 1.5, 1.4, 1.3, 0.90 ]
+                map_branches: &mapMasterToMain
+                  master: main
               -
                 alternatives: { source_lang: console, alternative_lang: go }
                 repo:   go-elasticsearch
                 path:   .doc/examples/doc/
                 exclude_branches:   [ 7.x, 7.15, 7.14, 7.13, 7.12, 7.11, 7.10, 7.9, 7.8, 7.7, 7.6, 7.5, 7.4, 7.3, 7.2, 7.1, 7.0, 6.8, 6.7, 6.6, 6.5, 6.4, 6.3, 6.2, 6.1, 6.0, 5.6, 5.5, 5.4, 5.3, 5.2, 5.1, 5.0, 2.4, 2.3, 2.2, 2.1, 2.0, 1.7, 1.6, 1.5, 1.4, 1.3, 0.90 ]
-                map_branches: &mapMasterToMain
-                  master: main
+                map_branches: *mapMasterToMain
               -
                 repo:   docs
                 path:   shared/versions/stack/{version}.asciidoc
@@ -455,8 +456,8 @@ contents:
               - title:      Ruby API
                 prefix:     ruby-api
                 current:    7.x
-                branches:   [ master, 7.x ]
-                live:       [ master, 7.x ]
+                branches:   [ {main: master}, 7.x ]
+                live:       [ main, 7.x ]
                 index:      docs/index.asciidoc
                 chunk:      1
                 tags:       Clients/Ruby