Add note about incompatibility of session_server with runner helm chart
Follow-up on the MR gitlab-runner!1575 (merged):
Interactive web terminals are not supported by gitlab-runner helm chart without additional modifications (see gitlab-runner#3713 (comment 125855357)).
This MR adds a note about it to https://gitlab.com/gitlab-org/gitlab-ce/ docs as well.
/cc @steveazz