Add ddev phpunit guidance to REAME.md.

README.md

@@ -72,10 +72,58 @@ lando ssh
 phpunit --filter=myTestName
 ```
 
+
+## Running PHPUnit tests in DDEV
+
+The included phpunit.xml.dist file contains configuration for automatically
+running the LocalGov Drupal test suite.
+
+The default .ddev/config.yml includes configuration for some extra domains that
+ddev and phpunit will need to resolve different microsite domains.
+
+When ddev starts, it will attempt to write these to /etc/hosts
+
+If DDEV cannot write to /etc/hosts, you may need to add these manually.
+
+If you are having problems runnign phpunit tests in DDEV, try adding the
+following to `/etc/hosts`
+
+```
+127.0.0.1 group-1.web group-2.web group-3.web group-4.web group-5.web
+```
+
+To allow html output, manually create a directory for browser output.
+
+```bash
+mkdir web/sites/simpletest/browser_output
+```
+
+To run all LocalGov Drupal tests from inside DDEV:
+
+```bash
+ddev ssh
+phpunit
+```
+
+To run all the tests for a specific module:
+
+```bash
+ddev ssh
+phpunit web/modules/contrib/localgov_my_module
+```
+
+Tests can be filtered using the `--filter` option. To only run a specific test:
+
+```bash
+ddev ssh
+phpunit --filter=myTestName
+```
+
+
 ## Maintainers
 
-This project is currently maintained by: 
+This project is currently maintained by:
 
  - Ekes: https://www.drupal.org/u/ekes
  - Finn Lewis: https://www.drupal.org/u/finn-lewis
- - Stephen Cox: https://www.drupal.org/u/stephen-cox 
+ - Stephen Cox: https://www.drupal.org/u/stephen-cox