Write a new README

Author: gselzer

README.md

@@ -1,50 +1,62 @@
-# no-package-cycles-enforcer-rule
+[![](https://github.com/scijava/scijava-packages-plugin/actions/workflows/build-main.yml/badge.svg)](https://github.com/scijava/scijava-packages-plugin/actions/workflows/build-main.yml)
 
-[![Build Status](https://travis-ci.org/andrena/no-package-cycles-enforcer-rule.svg)](https://travis-ci.org/andrena/no-package-cycles-enforcer-rule)
+[![](https://img.shields.io/maven-central/v/org.scijava/scijava-packages-plugin.svg)](http://search.maven.org/#search%7Cgav%7C1%7Cg%3A%22org.scijava%22%20AND%20a%3A%22scijava-packages-plugin%22)
 
-## About
+SciJava Packages Plugin
+====================
 
-This Maven Enforcer Rule checks your project for package cycles. It fails the build if any package cycle is found, showing you the packages and classes involved in the cycle.
+scijava-packages-plugin provides a set of [Maven Enforcer Plugin](https://maven.apache.org/enforcer/maven-enforcer-plugin/) rules for policing the package hierarchy at build time.
 
 ## Usage
 
-Add the following plugin to your POM:
+Currently, the only way to utilize these rules is by explicitly declaring it in the life cycle
 
 ```xml
 <plugin>
-    <artifactId>maven-enforcer-plugin</artifactId>
-    <version>3.0.0-M2</version>
-    <dependencies>
-        <dependency>
-            <groupId>de.andrena.tools.nopackagecycles</groupId>
-            <artifactId>no-package-cycles-enforcer-rule</artifactId>
-            <version>1.0.9</version>
-        </dependency>
-    </dependencies>
-    <executions>
-        <execution>
-            <id>enforce-no-package-cycles</id>
-            <goals>
-                <goal>enforce</goal>
-            </goals>
-            <phase>test</phase>
-            <configuration>
-                <rules>
-                    <NoPackageCyclesRule implementation="de.andrena.tools.nopackagecycles.NoPackageCyclesRule" />
-                </rules>
-            </configuration>
-        </execution>
-    </executions>
+	<artifactId>maven-enforcer-plugin</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.scijava</groupId>
+			<artifactId>scijava-packages-plugin</artifactId>
+			<version>0-SNAPSHOT</version>
+		</dependency>
+	</dependencies>
+	<executions>
+		...
+	</executions>
 </plugin>
 ```
 
+Rules
+====================
+
+# No Package Cycles
+[Circular dependencies](https://en.wikipedia.org/wiki/Circular_dependency) are usually considered poor practice. To prevent circular dependencies, add the following `execution`:
+
+```xml
+<execution>
+	<id>enforce-no-package-cycles</id>
+	<goals>
+		<goal>enforce</goal>
+	</goals>
+	<phase>test</phase>
+	<configuration>
+		<rules>
+			<NoPackageCyclesRule
+				implementation="org.scijava.packages.plugin.NoPackageCyclesRule" />
+		</rules>
+	</configuration>
+</execution>
+```
+
 ### Including test classes
 
 If you want to exclude tests from cycle checking, you can use the parameter `includeTests` which is set to true by default:
+
 ```xml
         ...
         <rules>
-            <NoPackageCyclesRule implementation="de.andrena.tools.nopackagecycles.NoPackageCyclesRule">
+            <NoPackageCyclesRule implementation="org.scijava.packages.plugin.NoPackageCyclesRule">
                 <includeTests>false</includeTests>
             </NoPackageCyclesRule>
         </rules>
@@ -61,7 +73,7 @@ If you want to exclude packages or restrict check to certain packages only, you
 ```xml
         ...
         <rules>
-            <NoPackageCyclesRule implementation="de.andrena.tools.nopackagecycles.NoPackageCyclesRule">
+            <NoPackageCyclesRule implementation="org.scijava.packages.plugin.NoPackageCyclesRule">
                 <includedPackages>
                     <includedPackage>myapp.code.good</includedPackage>
                 </includedPackages>
@@ -82,9 +94,30 @@ If you want to exclude packages or restrict check to certain packages only, you
         ...
 ```
 
+
+# No Subpackage Dependence
+Subpackage Dependence can throw a wrench into libraries wishing to follow the [Dependency Inversion principle](https://en.wikipedia.org/wiki/Dependency_inversion_principle). To prevent subpackage dependence, add the following `execution`:
+
+```xml
+<execution>
+	<id>enforce-no-subpackage-dependence</id>
+	<goals>
+		<goal>enforce</goal>
+	</goals>
+	<phase>test</phase>
+	<configuration>
+		<rules>
+			<NoSubpackageDependenceRule
+				implementation="org.scijava.packages.plugin.NoSubpackageDependenceRule" />
+		</rules>
+	</configuration>
+</execution>
+```
+
+
 ## See also
 
-* The original version by Daniel Seidewitz on [Stackoverflow](http://stackoverflow.com/questions/3416547/maven-jdepend-fail-build-with-cycles). Improved by showing all packages afflicted with cycles and the corresponding classes importing the conflicting packages.
+* The original version by Daniel Seidewitz on [Stackoverflow](http://stackoverflow.com/questions/3416547/maven-jdepend-fail-build-with-cycles). Improved by showing all packages afflicted with cycles and the corresponding classes importing the conflicting packages; this version was written [here](https://github.com/andrena/no-package-cycles-enforcer-rule). From there, the SciJava team made the behavior more extensible, making it easier to write and use more package-based rules.
 * [JDepend](https://github.com/clarkware/jdepend), the library being used to detect package cycles.
 * For more information about package cycles, see ["The Acyclic Dependencies Principle" by Robert C. Martin (Page 6)](http://www.objectmentor.com/resources/articles/granularity.pdf). 
 * The [Maven Enforcer Plugin](https://maven.apache.org/enforcer/maven-enforcer-plugin/)