add @SuppressWarnings and checkstyle-suppressions.xml opportunity (#13)

update README

README.md

@@ -2,22 +2,31 @@
 Our check style config based on Google style
 
 Usage example:
+
 ```xml
 <plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-checkstyle-plugin</artifactId>
-    <version>3.1.1</version>
+  <version>3.1.2</version>
+  <dependencies>
+    <dependency>
+      <groupId>com.puppycrawl.tools</groupId>
+      <artifactId>checkstyle</artifactId>
+      <version>8.41</version>
+    </dependency>
+  </dependencies>
   <executions>
     <execution>
       <id>validate</id>
       <phase>validate</phase>
       <configuration>
-                <configLocation>https://raw.githubusercontent.com/rbkmoney/java-checkstyle-config/master/conf/rbkmoney_google_checkstyle.xml</configLocation>
+        <configLocation>${checkstyle.config.path}</configLocation>
         <encoding>UTF-8</encoding>
         <failsOnError>true</failsOnError>
         <consoleOutput>true</consoleOutput>
         <violationSeverity>warning</violationSeverity>
         <includeTestSourceDirectory>true</includeTestSourceDirectory>
+        <suppressionsLocation>${checkstyle.config.suppressions.path}</suppressionsLocation>
       </configuration>
       <goals>
         <goal>check</goal>
@@ -26,3 +35,40 @@ Usage example:
   </executions>
 </plugin>
 ```
+
+### SuppressWarnings examples
+
+First path — override `${checkstyle.config.suppressions.path}` in project with `checkstyle-suppressions.xml` file and fill with your filters
+
+pom.xml:
+```xml
+<properties>
+    <checkstyle.config.suppressions.path>checkstyle-suppressions.xml</checkstyle.config.suppressions.path>
+</properties>
+```
+
+checkstyle-suppressions.xml:
+```xml
+<?xml version="1.0"?>
+
+<!DOCTYPE suppressions PUBLIC
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.0//EN"
+        "https://checkstyle.org/dtds/suppressions_1_0.dtd">
+
+<suppressions>
+<!--    EXAMPLE -->
+<!--    <suppress checks="LineLength"-->
+<!--              files="AppConfig.java"-->
+<!--              lines="0-9999"/>-->
+</suppressions>
+```
+
+Other path — use:
+```java 
+@SuppressWarnings({"checkstyle:%module_name%", "checkstyle:%module_name%""})
+``` 
+
+Example:
+```java 
+@SuppressWarnings({"checkstyle:parametername", "checkstyle:localvariablename"})
+``` 

conf/checkstyle-suppressions.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+
+<!DOCTYPE suppressions PUBLIC
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.0//EN"
+        "https://checkstyle.org/dtds/suppressions_1_0.dtd">
+
+<suppressions>
+<!--    EXAMPLE -->
+<!--    <suppress checks="LineLength"-->
+<!--              files="AppConfig.java"-->
+<!--              lines="0-9999"/>-->
+</suppressions>

conf/rbkmoney_google_checkstyle.xml

@@ -33,6 +33,7 @@
                   default="checkstyle-suppressions.xml" />
         <property name="optional" value="true"/>
     </module>
+    <module name="SuppressWarningsFilter"/>
 
     <!-- Checks for whitespace                               -->
     <!-- See http://checkstyle.org/config_whitespace.html -->
@@ -48,6 +49,7 @@
     </module>
 
     <module name="TreeWalker">
+        <module name="SuppressWarningsHolder"/>
         <module name="OuterTypeFilename"/>
         <module name="IllegalTokenText">
             <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>