docs: add Angular 12 support information (#42124)

Added angular 12 suppport information in release document

Closes #42111

PR Close #42124

aio/content/guide/releases.md

@@ -107,7 +107,8 @@ The following table provides the status for Angular versions under support.
 
 Version | Status | Released     | Active Ends  | LTS Ends
 ------- | ------ | ------------ | ------------ | ------------
-^11.0.0 | Active | Nov 11, 2020 | May 11, 2021 | May 11, 2022
+^12.0.0 | Active | May 12, 2021 | Nov 12, 2021 | Nov 12, 2022
+^11.0.0 | LTS    | Nov 11, 2020 | May 11, 2021 | May 11, 2022
 ^10.0.0 | LTS    | Jun 24, 2020 | Dec 24, 2020 | Dec 24, 2021
 ^9.0.0  | LTS    | Feb 06, 2020 | Aug 06, 2020 | Aug 06, 2021