Update README.md

Author: matthewstyler

README.md

@@ -1,2 +1,81 @@
 # Checkstyle Suppression Generator
 
+A gem that takes as input the output of a maven checkstyle plugin checkstyle:check goal and generates a suppressions.xml file.
+
+Example Input:
+```sh
+[INFO] Scanning for projects...
+[INFO] ------------------------------------------------------------------------
+[INFO] Reactor Build Order:
+[INFO] 
+[INFO] my-project                                                         [jar]
+[INFO]  ------------------< com.my-project:my-project >------------------
+[INFO] Building my-project 0.0.1-SNAPSHOT                          [1/1]
+[INFO]   from my-project/pom.xml
+[INFO] --------------------------------[ jar ]---------------------------------
+[INFO] 
+[INFO] --- checkstyle:3.3.0:check (default-cli) @ my-project ---
+[WARNING] src/main/java/com/test/DEF.java:[147,4] (coding) OverloadMethodsDeclarationOrder: All overloaded methods should be placed next to each other. Placing non-overloaded methods in between overloaded methods with the same type is a violation. Previous overloaded method located at line '119'.
+[WARNING] src/main/java/com/test/ABC.java:[26,11] (sizes) ParameterNumber: More than 7 parameters (found 9).
+[WARNING] src/main/java/com/test/ABC.java:[103,4] (coding) ReturnCount: Return count is 6 (max allowed for non-void methods/lambdas is 4).
+[WARNING] src/main/java/com/test/ABC.java:[103,4] (metrics) NPathComplexity: NPath Complexity is 720 (max allowed is 200).
+[INFO] ------------------------------------------------------------------------
+[INFO] Reactor Summary for my-project 0.0.1-SNAPSHOT:
+[INFO] 
+[INFO] my-project .................................. FAILURE [  1.957 s]
+[INFO] ------------------------------------------------------------------------
+[INFO] BUILD FAILURE
+[INFO] ------------------------------------------------------------------------
+[INFO] Total time:  2.841 s
+[INFO] Finished at: 2023-12-20T16:31:35-05:00
+[INFO] ------------------------------------------------------------------------
+[ERROR] Failed to execute goal org.apache.maven.plugins:maven-checkstyle-plugin:3.3.0:check (default-cli) on project my-project: You have 4 Checkstyle violations. -> [Help 1]
+[ERROR] 
+[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
+[ERROR] Re-run Maven using the -X switch to enable full debug logging.
+[ERROR] 
+[ERROR] For more information about the errors and possible solutions, please read the following articles:
+[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
+[ERROR] 
+[ERROR] After correcting the problems, you can resume the build with the command
+[ERROR]   mvn <args> -rf :my-project
+
+```
+
+Output:
+
+```xml
+<?xml version="1.0"?>
+<!DOCTYPE suppressions PUBLIC "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+      "https://checkstyle.org/dtds/suppressions_1_2.dtd">
+
+<suppressions>
+
+	<suppress checks="OverloadMethodsDeclarationOrder" files="src/main/java/com/test/DEF.java"/>
+	<suppress checks="ParameterNumber" files="src/main/java/com/test/ABC.java"/>
+	<suppress checks="ReturnCount" files="src/main/java/com/test/ABC.java"/>
+	<suppress checks="NPathComplexity" files="src/main/java/com/test/ABC.java"/>
+
+</suppressions>
+
+```
+
+
+## Command Line Usage
+```sh
+Usage: checkstyle-suppression-generator command [OPTIONS]
+       CHECKSTYLE_OUTPUT_FILE(STRING) [O=O]
+
+Generate a Java checkstyle suppressions.xml file from a checkstyle:check output.
+
+
+Arguments:
+  CHECKSTYLE_OUTPUT_FILE(STRING)  Output from checkstyle:check goal
+
+Keywords:
+  O=O  Name of the suppressions file to be generated (default
+       "suppressions.xml")
+
+Options:
+  -h, --help  Print usage
+```