Drop HoundCI references

Before, we used to use HoundCI for all our linting needs. Nowadays we
tend to use local linting solutions and CI services. We dropped
references to HoundCI from the guides.

Co-authored-by: Valeria Graffeo <valeria@thoughtbot.com>
Co-authored-by: Jose Blanco <jose.blanco@thoughtbot.com>
Co-authored-by: Nick Charlton <nc@thoughtbot.com>

Author: 4 people

README.md

@@ -1,7 +1,5 @@
 # Guides
 
-[![Reviewed by Hound](https://img.shields.io/badge/Reviewed_by-Hound-8E64B0.svg)](https://houndci.com)
-
 Guides for working together, getting things done, programming well, and
 programming in style.
 

general/README.md

@@ -14,11 +14,9 @@ Style and best practices that apply to all languages and frameworks.
 
 ## Code Review
 
-Use [Hound] to automatically review your GitHub pull requests for style guide
+Use a linter to automatically review your GitHub pull requests for style guide
 violations.
 
-[hound]: https://houndci.com
-
 ## Formatting
 
 - Avoid inline comments.