Add changelog for 211
This MR was automatically created from CI, https://gitlab.com/gitlab-org/gitter/gitter-android-app/-/jobs/135824318
We copied CURRENT_VERSION.txt
-> 211.txt
This MR was automatically created from CI, https://gitlab.com/gitlab-org/gitter/gitter-android-app/-/jobs/135824318
We copied CURRENT_VERSION.txt
-> 211.txt