Docs: Fix for asciidoctor (#47876)

Asciidoctor is a bit more picky about somethings. This fixes them for
it.

docs/api/spaces-management.asciidoc

@@ -10,7 +10,7 @@ Manage your {kib} spaces.
 * <<spaces-api-get-all, Get all {kib} spaces API>>
 * <<spaces-api-delete, Delete space API>>
 * <<spaces-api-copy-saved-objects, Copy saved objects to space API>>
-*<<spaces-api-resolve-copy-saved-objects-conflicts , Resolve copy saved objects to space conflicts API>>
+* <<spaces-api-resolve-copy-saved-objects-conflicts, Resolve copy saved objects to space conflicts API>>
 
 include::spaces-management/post.asciidoc[]
 include::spaces-management/put.asciidoc[]

docs/developer/plugin/development-plugin-resources.asciidoc

@@ -28,13 +28,13 @@ node scripts/generate_plugin my_plugin_name # replace "my_plugin_name" with your
 The Kibana directory must be named `kibana`, and your plugin directory should be located in the root of `kibana` in a `plugins` directory, for example:
 
 ["source","shell"]
------------
+----
 .
 └── kibana
     └── plugins
         ├── foo-plugin
         └── bar-plugin
---------
+----
 
 [float]
 ==== References in the code

docs/user/extend.asciidoc

@@ -10,6 +10,6 @@
 
 --
 
-include::graph/index.asciidoc[leveloffset=+1]
+include::graph/index.asciidoc[]
 
 include::ml/index.asciidoc[]