code: public static FileConfigSourceStep servletContextDirectory() {
  
          return new BaseFileConfigSourceStep() {
  
              @Override
              public NamedConfigSource by(PathSpecification pathSpecification) {
  
                  checkNotNull(pathSpecification);
  
                  return
                      new ServletContextDirectoryConfigSource(pathSpecification)
                      .named(
                          String.format(
                              "servlet context directory %s",
                              pathSpecification.name()
                          )
                      );
              }
          };
      }
docs: Config loaded from a file located at
  {@code [path]/[servlet context path]}.
  
  <ul>
  <li>{@code [path]} is determined by a {@link PathSpecification}</li>
  <li>{@code [servlet context path]} is the
  {@link ServletContextPath} from the {@link ConfigFactory}'s
  {@link Bindings}.</li>
  </ul>
  
  <p>The config will be empty if any of the following are true:</p>
  
  <ul>
  <li>If {@link PathSpecification#path(Bindings)}
  .{@link OptionalPath#isPresent() isPresent()}
  is {@code false}</li>
  <li>If no {@link ServletContextPath} is bound</li>
  <li>If no config file exists at
  {@code [path]/[servlet context path]}</li>
  </ul>