docs(docs): update guide (#1853)

Author: koooge

.github/CONTRIBUTING.md

@@ -57,9 +57,6 @@ $ yarn test:unit
 
 # run the full test suite, include linting / type checking
 $ yarn test
-
-# run tests against src files only. Allows inline debugging.
-$ yarn test:unit:only:dev
 ```
 
 There are some other scripts available in the `scripts` section of the `package.json` file.