Remove Slack

Author: RichardLitt

README.md

@@ -26,8 +26,6 @@ Alternatively, you can run the application locally:
 
 Please contribute! Open an issue, make a pull request, reach out for help. This organization is entirely volunteer run, and your contributions are important.
 
-We use Slack to discuss our changes and to talk about community issues, as well as GitHub. Join our community slack [here](https://slack.opencollective.org). Join the channel `#sustainoss` to talk to us.
-
 If you need help with using GitHub in order to open an issue, sign up for an account, come back to this page, and open an issue by [clicking here](https://github.com/sustainers/sustainers.github.io/issues/new). Ping one of us on Slack if you need help.
 
 ### Blog posts

_config.yml

@@ -47,7 +47,6 @@ exclude:
 
 params:
   github:           "https://github.com/sustainers"
-  slack:            "https://slack.opencollective.org"
   discourse:        "https://discourse.sustainoss.org"
 
 # Social-related stuff

_includes/footer.html

@@ -53,11 +53,6 @@
                 {%- include icons/github.svg -%}
               </a>
             </li>
-            <li class="list-inline-item mx-1 mx-sm-3">
-              <a href="{{ site.params.slack }}" rel="noopener" target="_blank" title="Slack">
-                {%- include icons/slack.svg -%}
-              </a>
-            </li>
 <!--             <li class="list-inline-item mx-1 mx-sm-3">
               <a href="{{ site.params.twitter }}" rel="noopener" target="_blank" title="Twitter">
                 {%- include icons/twitter.svg -%}