docs: Prepare for new sub tree

See #11925

docs/content/en/troubleshooting/deprecation.md

@@ -1,50 +0,0 @@
----
-title: Deprecation
-description: The Hugo project follows a formal and consistent process to deprecate functions, methods, and configuration settings.
-categories: [troubleshooting]
-keywords: []
-menu:
-  docs:
-    parent: troubleshooting
-    weight: 50
-weight: 50
----
-
-When a project _deprecates_ something, they are telling its users:
-
-1. Don't use Thing One anymore.
-2. Use Thing Two instead.
-3. We're going to remove Thing One at some point in the future.
-
-[reasons for deprecation]: https://en.wikipedia.org/wiki/Deprecation
-
-Common [reasons for deprecation]:
-
-- A feature has been replaced by a more powerful alternative.
-- A feature contains a design flaw.
-- A feature is considered extraneous, and will be removed in the future in order to simplify the system as a whole.
-- A future version of the software will make major structural changes, making it impossible or impractical to support older features.
-- Standardization or increased consistency in naming.
-- A feature that once was available only independently is now combined with its co-feature.
-
-After the project team deprecates something in code, Hugo will:
-
-1. Log an INFO message for 6 minor releases[^1]
-2. Log a WARN message for another 6 minor releases
-3. Log an ERROR message and fail the build thereafter
-
-To see the INFO messages, you must use the `--logLevel` command line flag:
-
-```text
-hugo --logLevel info
-```
-
-To limit the output to deprecation notices:
-
-```text
-hugo --logLevel info | grep deprecate
-```
-
-Run the above command every time you upgrade Hugo.
-
-[^1]: For example, v0.1.1 => v0.2.0 is a minor release.