Slack -> Gitter

CONTRIBUTING.md

 ## Contributing to Caddy
 
-**[Join us on Slack](https://gophers.slack.com/messages/caddy/)** to chat with 
-other Caddy developers! ([Request an invite](http://bit.ly/go-slack-signup), 
-then join the #caddy channel.)
+**[Join our dev chat on Gitter](https://gitter.im/mholt/caddy)** to chat with
+other Caddy developers! (Dev chat only; try our
+[support room](https://gitter.im/caddyserver/support) for help or
+[general](https://gitter.im/caddyserver/general) for anything else.)
 
 This project gladly accepts contributions and we encourage interested users to 
 get involved!
@@ -11,24 +12,25 @@ get involved!
 #### For small tweaks, bug fixes, and tests
 
 Submit [pull requests](https://github.com/mholt/caddy/pulls) at any time. 
-Thank you for helping out in simple ways! Bug fixes should be under test to 
-assert correct behavior.
+Bug fixes should be under test to assert correct behavior. Thank you for
+helping out in simple ways!
 
 
 #### Ideas, questions, bug reports
 
-You should totally [open an issue](https://github.com/mholt/caddy/issues) with 
-your ideas, questions, and bug reports, if one does not already exist for it. 
-Bug reports should state expected behavior and contain clear instructions for 
-reproducing the problem. 
+Feek free to [open an issue](https://github.com/mholt/caddy/issues) with your
+ideas, questions, and bug reports, if one does not already exist for it. Bug
+reports should state expected behavior and contain clear instructions for
+isolating and reproducing the problem.
 See [How to Report Bugs Effectively](http://www.chiark.greenend.org.uk/~sgtatham/bugs.html).
 
+
 #### New features
 
 Before submitting a pull request, please open an issue first to discuss it and 
 claim it. This prevents overlapping efforts and keeps the project in-line with 
 its goals. If you prefer to discuss the feature privately, you can reach other 
-developers on Slack or you may email me directly. (My email address is below.)
+developers on Gitter or you may email me directly. (My email address is below.)
 
 And don't forget to write tests for new features!
 

README.md

 [![Caddy](https://caddyserver.com/resources/images/caddy-boxed.png)](https://caddyserver.com)
 
+[![Dev Chat](https://img.shields.io/badge/dev%20chat-gitter-ff69b4.svg?style=flat-square&label=dev+chat&color=ff69b4)](https://gitter.im/mholt/caddy) 
 [![Documentation](https://img.shields.io/badge/godoc-reference-blue.svg?style=flat-square)](https://godoc.org/github.com/mholt/caddy) 
 [![Linux Build Status](https://img.shields.io/travis/mholt/caddy.svg?style=flat-square&label=linux+build)](https://travis-ci.org/mholt/caddy) 
 [![Windows Build Status](https://img.shields.io/appveyor/ci/mholt/caddy.svg?style=flat-square&label=windows+build)](https://ci.appveyor.com/project/mholt/caddy)
@@ -139,9 +140,10 @@ packages that each Caddy package imports.
 
 ## Contributing
 
-**[Join us on Slack](https://gophers.slack.com/messages/caddy/)** to chat with
-other Caddy developers! ([Request an invite](http://bit.ly/go-slack-signup),
-then join the #caddy channel.)
+**[Join our dev chat on Gitter](https://gitter.im/mholt/caddy)** to chat with
+other Caddy developers! (Dev chat only; try our
+[support room](https://gitter.im/caddyserver/support) for help or
+[general](https://gitter.im/caddyserver/general) for anything else.)
 
 This project would not be what it is without your help. Please see the
 [contributing guidelines](https://github.com/mholt/caddy/blob/master/CONTRIBUTING.md)