content: remove link to the Slack channel

Slack channel is not the primary channel but a support
channel. From the text, the readers assume that it will
be the canonical communication channel.

Change-Id: I6440b3e2f6089f99c038d7937b77b6fb6d301f61
Reviewed-on: https://go-review.googlesource.com/40314
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Kevin Burke <kev@inburke.com>
diff --git a/content/developer-experience.article b/content/developer-experience.article
index edc807d..4122127 100644
--- a/content/developer-experience.article
+++ b/content/developer-experience.article
@@ -34,8 +34,6 @@
 We are looking for additional people to help with contributing
 code, writing documentation, sharing feedback and experiences
 (user stories), reviewing contributions, and more. If you are
-interested in any of our current areas of focus, please join
-us on the [[https://gophers.slack.com/archives/devexp][#devexp]] channel on the
-[[https://invite.slack.golangbridge.org/][Gophers Slack]] and subscribe to the
+interested in any of our current areas of focus, please subscribe to the
 [[https://groups.google.com/forum/#!forum/golang-devexp][golang-devexp]]
 mailing list.