Tweak lodash, shimIsPlainObject, shimKeys, and reduce function docs. [ci skip]

Former-commit-id: f24dd4de2a5a6c8103f26d000f1f16b5be3d8165

dist/lodash.underscore.js

@@ -144,7 +144,7 @@
   /*--------------------------------------------------------------------------*/
 
   /**
-   * Creates a `lodash` object, that wraps the given `value`, to enable method
+   * Creates a `lodash` object, which wraps the given `value`, to enable method
    * chaining.
    *
    * In addition to Lo-Dash methods, wrappers also have the following `Array` methods:
@@ -182,6 +182,26 @@
    * @category Chaining
    * @param {Mixed} value The value to wrap in a `lodash` instance.
    * @returns {Object} Returns a `lodash` instance.
+   * @example
+   *
+   * var wrapped = _([1, 2, 3]);
+   *
+   * // returns an unwrapped value
+   * wrapped.reduce(function(sum, num) {
+   *   return sum + num;
+   * });
+   * // => 6
+   *
+   * // returns a wrapped value
+   * var squares = wrapped.map(function(num) {
+   *   return num * num;
+   * });
+   *
+   * _.isArray(squares);
+   * // => false
+   *
+   * _.isArray(squares.value());
+   * // => true
    */
   function lodash(value) {
     return (value instanceof lodash)
@@ -486,7 +506,7 @@
   };
 
   /**
-   * A fallback implementation of `Object.keys` that produces an array of the
+   * A fallback implementation of `Object.keys` which produces an array of the
    * given object's own enumerable property names.
    *
    * @private
@@ -2030,7 +2050,7 @@
   }
 
   /**
-   * Reduces a `collection` to a value that is the accumulated result of running
+   * Reduces a `collection` to a value which is the accumulated result of running
    * each element in the `collection` through the `callback`, where each successive
    * `callback` execution consumes the return value of the previous execution.
    * If `accumulator` is not passed, the first element of the `collection` will be