Add docs on code reviews.

docs/code_review.md

@@ -0,0 +1,40 @@
+# Code Review in the-build
+
+From your project where you have installed the-build, run `vendor/bin/phing code-review` to run the default set of code reviews. This target is provided in the default `build.xml` created for your project during install.
+
+This will review your code with:
+
+* Drupal Codesniffer
+* PHPmd
+* PHP Lint
+* PHPtodo
+
+Generally, you should configure your `build.xml` to run code reviews as part of your `test` target so that developers run the reviews by default.
+
+### PHP Lint
+
+PHP Lint uses the PHP interpreter directly to check for syntax errors. There is no configuration for this review.
+
+### [PHPMD](https://phpmd.org/)
+
+A more complicated and more general PHP code review than the Drupal Codesniffer standard. The default config for this review can be found within the-build at `conf/phpmd.xml`. To customize this config, copy that file to your project's `conf/` directory and add the build property:
+
+```
+phpmd.rulesets=conf/phpmd.xml
+```
+
+### Drupal Codesniffer
+
+Runs codesniffer using the standard provided by Drupal's [Coder](https://www.drupal.org/project/coder) module. Generally, you should not change the configuration for this review, but if do need to you can provide a different standard:
+
+```
+drupal_code_sniffer.standard=vendor/drupal/coder/coder_sniffer/Drupal/ruleset.xml
+```
+
+### [PHP To-do Finder](https://github.com/nilportugues/php-todo-finder)
+
+Sets a threshold for the number of "to do" comments allowable in a codebase. The default config for this review can be found within the-build at `conf/php_todo_finder.yml`. To customize this config, copy that file to your project's `conf/` directory and add the build property:
+
+```
+phptodo.config=conf/php_todo_finder.yml
+```