docs(model+query): add lean() option to Model helpers

Fix #5996

lib/model.js

@@ -1686,6 +1686,7 @@ Model.$where = function $where() {
  * @param {Object} [conditions]
  * @param {Object} [update]
  * @param {Object} [options] optional see [`Query.prototype.setOptions()`](http://mongoosejs.com/docs/api.html#query_Query-setOptions)
+ * @param {Object} [options.lean] if truthy, mongoose will return the document as a plain JavaScript object rather than a mongoose document. See [`Query.lean()`](http://mongoosejs.com/docs/api.html#query_Query-lean).
  * @param {Function} [callback]
  * @return {Query}
  * @see mongodb http://www.mongodb.org/display/DOCS/findAndModify+Command
@@ -1805,6 +1806,7 @@ Model.findOneAndUpdate = function(conditions, update, options, callback) {
  * @param {Object|Number|String} id value of `_id` to query by
  * @param {Object} [update]
  * @param {Object} [options] optional see [`Query.prototype.setOptions()`](http://mongoosejs.com/docs/api.html#query_Query-setOptions)
+ * @param {Object} [options.lean] if truthy, mongoose will return the document as a plain JavaScript object rather than a mongoose document. See [`Query.lean()`](http://mongoosejs.com/docs/api.html#query_Query-lean).
  * @param {Function} [callback]
  * @return {Query}
  * @see Model.findOneAndUpdate #model_Model.findOneAndUpdate
@@ -2968,7 +2970,8 @@ Model.aggregate = function aggregate() {
  * - `lean` {Boolean} return the raw object instead of the Mongoose Model
  *
  * @param {Object} conditions an object that specifies the match condition (required)
- * @param {Object} options for the geoSearch, some (near, maxDistance) are required
+ * @param {Object} [options] for the geoSearch, some (near, maxDistance) are required
+ * @param {Object} [options.lean] if truthy, mongoose will return the document as a plain JavaScript object rather than a mongoose document. See [`Query.lean()`](http://mongoosejs.com/docs/api.html#query_Query-lean).
  * @param {Function} [callback] optional callback
  * @return {Promise}
  * @see http://docs.mongodb.org/manual/reference/command/geoSearch/

lib/query.js

@@ -1002,11 +1002,11 @@ Query.prototype.read = function read(pref, tags) {
  * - [readPreference](http://docs.mongodb.org/manual/applications/replication/#read-preference)
  * - [hint](http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-%24hint)
  *
- * The following options are only for `update()`, `updateOne()`, `updateMany()`, `replaceOne()`, and `findOneAndUpdate()`:
+ * The following options are only for `update()`, `updateOne()`, `updateMany()`, `replaceOne()`, `findOneAndUpdate()`, and `findByIdAndUpdate()`:
  * - [upsert](https://docs.mongodb.com/manual/reference/method/db.collection.update/)
  * - [writeConcern](https://docs.mongodb.com/manual/reference/method/db.collection.update/)
  *
- * The following options are only for `find()`, `findOne()`, `findById()`, and `findOneAndUpdate()`:
+ * The following options are only for `find()`, `findOne()`, `findById()`, `findOneAndUpdate()`, and `findByIdAndUpdate()`:
  * - [lean](./api.html#query_Query-lean)
  *
  * The following options are only for all operations **except** `update()`, `updateOne()`, `updateMany()`, `remove()`, `deleteOne()`, and `deleteMany()`:

test/docs/validation.test.js

@@ -534,12 +534,12 @@ describe('validation docs', function() {
  * One final detail worth noting: update validators **only** run on the
  * following update operators:
  *
- * \* `$set`
- * \* `$unset`
- * \* `$push` (>= 4.8.0)
- * \* `$addToSet` (>= 4.8.0)
- * \* `$pull` (>= 4.12.0)
- * \* `$pullAll` (>= 4.12.0)
+ * - `$set`
+ * - `$unset`
+ * - `$push` (>= 4.8.0)
+ * - `$addToSet` (>= 4.8.0)
+ * - `$pull` (>= 4.12.0)
+ * - `$pullAll` (>= 4.12.0)
  *
  * For instance, the below update will succeed, regardless of the value of
  * `number`, because update validators ignore `$inc`. Also, `$push`,