Update docs markdown file weight to make it clear (#23909)

For Docusaurus, it needs a meta data named `sidebar_position`, so we
copy all `weight` under `menu/sidebar` as top meta key.

docs/content/doc/contributing/localization.zh-cn.md

@@ -2,7 +2,7 @@
 date: "2016-12-01T16:00:00+02:00"
 title: "本地化"
 slug: "localization"
-weight: 10
+weight: 20
 toc: false
 draft: false
 menu:

docs/content/doc/contributing/localization.zh-tw.md

@@ -2,7 +2,7 @@
 date: "2016-12-01T16:00:00+02:00"
 title: "在地化"
 slug: "localization"
-weight: 10
+weight: 20
 toc: false
 draft: false
 menu:

docs/content/doc/contributing/translation.de-de.md

@@ -1,7 +1,7 @@
 ---
 date: "2021-01-22T00:00:00+02:00"
 title: "Übersetzungs Richtlinien"
-weight: 10
+weight: 70
 toc: true
 draft: false
 menu:

docs/content/doc/contributing/translation.en-us.md

@@ -1,7 +1,7 @@
 ---
 date: "2021-01-22T00:00:00+02:00"
 title: "Translation Guidelines"
-weight: 10
+weight: 70
 toc: true
 draft: false
 menu: