Add `language_bcp47` tag (#4753)

* fix ms_terms

* fix ted_talks_iwslt

* move tags to language_bcp47

* fix bad codes

* add language_details and language_bcp47 in DatasetMetadata

* more fixes

* fix wiki_dpr

Commit from https://github.com/huggingface/datasets/commit/aa48a29d1304167dff37cef0ed7542f29376ee2d

README.md

@@ -4,46 +4,46 @@ annotations_creators:
 language_creators:
 - found
 language:
-- ca
-- de
-- es
-- fi
-- hi
-- id
-- ko
-- ms
-- pl
-- ru
-- sr
-- tl
-- vi
 - ar
+- bg
+- ca
 - cs
+- da
+- de
 - el
+- en
+- es
 - et
+- fa
+- fi
 - fr
+- he
+- hi
 - hr
+- hu
+- id
 - it
+- ja
+- ko
 - lt
+- lv
+- ms
 - nl
+- 'no'
+- pl
 - pt
-- sk
-- sv
-- tr
-- zh
-- bg
-- da
-- en
-- fa
-- he
-- hu
-- ja
-- lv
-- "no"
 - ro
+- ru
+- sk
 - sl
+- sr
+- sv
 - th
+- tl
+- tr
 - uk
+- vi
+- zh
 license:
 - unknown
 multilinguality: