Update changelogs for 2021.07.12 release.
+v2021.07.12
+===========
+* [Stable channel] IntelliJ: Compatible with IntelliJ CE/UE 2021.1.
+* [Stable channel] CLion: Compatible with CLion 2021.1.
+
v2021.06.29
===========
* [Beta channel] IntelliJ: Compatible with IntelliJ CE/UE 2021.1.
