Add guidelines for working with localized content (#11415)

Clarify about where to look for specific l10n tasks

More accurate link pointer

Update link for upstream contributions

content/en/docs/contribute/intermediate.md

@@ -806,6 +806,18 @@ content. See [Localization](/docs/contribute/localization/) and ask on the
 [kubernetes-sig-docs mailing list](https://groups.google.com/forum/#!forum/kubernetes-sig-docs)
 or in `#sig-docs` on Slack if you are interested in helping out.
 
+### Working with localized content
+
+Follow these guidelines for working with localized content:
+
+- Limit PRs to a single language. 
+
+   Each language has its own reviewers and approvers.
+
+- Reviewers, verify that PRs contain changes to only one language.
+
+   If a PR contains changes to source in more than one language, ask the PR contributor to open separate PRs for each language.
+
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