Merge commit '9b0050e9aabe4be65c78ccf292a348f309d50ccd' as 'docs'

```
git subtree add --prefix=docs/ https://github.com/gohugoio/hugoDocs.git master --squash
```

Closes #11925

docs/content/en/commands/hugo_gen_doc.md

@@ -0,0 +1,50 @@
+---
+title: "hugo gen doc"
+slug: hugo_gen_doc
+url: /commands/hugo_gen_doc/
+---
+## hugo gen doc
+
+Generate Markdown documentation for the Hugo CLI.
+
+### Synopsis
+
+Generate Markdown documentation for the Hugo CLI.
+			This command is, mostly, used to create up-to-date documentation
+	of Hugo's command-line interface for https://gohugo.io/.
+
+	It creates one Markdown file per command with front matter suitable
+	for rendering in Hugo.
+
+```
+hugo gen doc [flags] [args]
+```
+
+### Options
+
+```
+      --dir string   the directory to write the doc. (default "/tmp/hugodoc/")
+  -h, --help         help for doc
+```
+
+### Options inherited from parent commands
+
+```
+      --clock string               set the clock used by Hugo, e.g. --clock 2021-11-06T22:30:00.00+09:00
+      --config string              config file (default is hugo.yaml|json|toml)
+      --configDir string           config dir (default "config")
+      --debug                      debug output
+  -d, --destination string         filesystem path to write files to
+  -e, --environment string         build environment
+      --ignoreVendorPaths string   ignores any _vendor for module paths matching the given Glob pattern
+      --logLevel string            log level (debug|info|warn|error)
+      --quiet                      build in quiet mode
+  -s, --source string              filesystem path to read files relative from
+      --themesDir string           filesystem path to themes directory
+  -v, --verbose                    verbose output
+```
+
+### SEE ALSO
+
+* [hugo gen](/commands/hugo_gen/)	 - A collection of several useful generators.
+