Update docs

Author: owen-mc

java/ql/src/semmle/code/java/JDK.qll

@@ -178,7 +178,7 @@ class TypeFile extends Class {
 
 // --- Standard methods ---
 /**
- * Any of the methods named `command` on class `java.lang.ProcessBuilder`.
+ * Any constructor of class `java.lang.ProcessBuilder`.
  */
 class ProcessBuilderConstructor extends Constructor, ExecCallable {
   ProcessBuilderConstructor() { this.getDeclaringType() instanceof TypeProcessBuilder }

java/ql/src/semmle/code/java/frameworks/apache/Exec.qll

@@ -2,11 +2,13 @@
 import semmle.code.java.Type
 import semmle.code.java.security.ExternalProcess
 
-library class TypeCommandLine extends Class {
+/** The class `org.apache.commons.exec.CommandLine`. */
+private class TypeCommandLine extends Class {
   TypeCommandLine() { hasQualifiedName("org.apache.commons.exec", "CommandLine") }
 }
 
-library class MethodCommandLineParse extends Method, ExecCallable {
+/** The `parse()` method of the class `org.apache.commons.exec.CommandLine`. */
+private class MethodCommandLineParse extends Method, ExecCallable {
   MethodCommandLineParse() {
     getDeclaringType() instanceof TypeCommandLine and
     hasName("parse")
@@ -15,7 +17,8 @@ library class MethodCommandLineParse extends Method, ExecCallable {
   override int getAnExecutedArgument() { result = 0 }
 }
 
-library class MethodCommandLineAddArguments extends Method, ExecCallable {
+/** The `addArguments()` method of the class `org.apache.commons.exec.CommandLine`. */
+private class MethodCommandLineAddArguments extends Method, ExecCallable {
   MethodCommandLineAddArguments() {
     getDeclaringType() instanceof TypeCommandLine and
     hasName("addArguments")

java/ql/src/semmle/code/java/security/ExternalProcess.qll

@@ -4,9 +4,12 @@ import semmle.code.java.JDK
 import semmle.code.java.frameworks.apache.Exec
 
 /**
- * A method that executes a command.
+ * A callable that executes a command.
  */
 abstract class ExecCallable extends Callable {
+  /**
+   * Gets the index of an argument that will be part of the command that is executed.
+   */
   abstract int getAnExecutedArgument();
 }