Tune Checkstyle config to reflect the current project state

Author: valfirst

config/checkstyle/checkstyle.xml

@@ -48,10 +48,6 @@
         <property name="fileNamePattern" value="module\-info\.java$"/>
     </module>
 
-    <!-- Checks that a package-info.java file exists for each package.     -->
-    <!-- See https://checkstyle.org/config_javadoc.html#JavadocPackage -->
-    <module name="JavadocPackage"/>
-
     <!-- Checks whether files end with a new line.                        -->
     <!-- See https://checkstyle.org/config_misc.html#NewlineAtEndOfFile -->
     <module name="NewlineAtEndOfFile"/>
@@ -65,6 +61,7 @@
     <module name="FileLength"/>
     <module name="LineLength">
       <property name="fileExtensions" value="java"/>
+      <property name="max" value="120"/>
     </module>
 
     <!-- Checks for whitespace                               -->
@@ -94,9 +91,6 @@
         <module name="InvalidJavadocPosition"/>
         <module name="JavadocMethod"/>
         <module name="JavadocType"/>
-        <module name="JavadocVariable"/>
-        <module name="JavadocStyle"/>
-        <module name="MissingJavadocMethod"/>
 
         <!-- Checks for Naming Conventions.                  -->
         <!-- See https://checkstyle.org/config_naming.html -->
@@ -154,27 +148,22 @@
         <!-- See https://checkstyle.org/config_coding.html -->
         <module name="EmptyStatement"/>
         <module name="EqualsHashCode"/>
-        <module name="HiddenField"/>
         <module name="IllegalInstantiation"/>
         <module name="InnerAssignment"/>
-        <module name="MagicNumber"/>
         <module name="MissingSwitchDefault"/>
         <module name="MultipleVariableDeclarations"/>
         <module name="SimplifyBooleanExpression"/>
         <module name="SimplifyBooleanReturn"/>
 
         <!-- Checks for class design                         -->
         <!-- See https://checkstyle.org/config_design.html -->
-        <module name="DesignForExtension"/>
         <module name="FinalClass"/>
         <module name="HideUtilityClassConstructor"/>
         <module name="InterfaceIsType"/>
-        <module name="VisibilityModifier"/>
 
         <!-- Miscellaneous other checks.                   -->
         <!-- See https://checkstyle.org/config_misc.html -->
         <module name="ArrayTypeStyle"/>
-        <module name="FinalParameters"/>
         <module name="TodoComment"/>
         <module name="UpperEll"/>