Fixed examples for new data

Author: dfreniche

docs/50-counting-sorting/10-sorting.mdx

@@ -2,7 +2,7 @@
 
 We can sort our results using the `$sort` stage. We need to sort on a field, being 1 ascending and -1 descending order.
 
-Let's get all books from 1984, sorted by number of pages. We'll only show the title, pages and authors.
+💻 Let's get all books from 1984, sorted by number of pages. We'll only show the title, pages and authors.
 
 ```js
 let booksFrom1984 = {$match: {year: 1984}};
@@ -16,8 +16,9 @@ db.books.aggregate([
 ]);
 ```
 
-As we can see, we don't get any `pages` info as these documents don't have that information, hence is `null` and gets sorted as less than any number. We can sort the other way around:
+As we can see, books with no `pages` info appear first. These documents don't have that information, hence `pages` is `null` and gets sorted as less than any number. 
 
+💻 We can sort the other way around:
 
 ```js
 let booksFrom1984 = {$match: {year: 1984}};

docs/60-lookups/1-lookups.mdx

@@ -57,8 +57,7 @@ db.authors.aggregate([
 The nice part is that we can extract that pipeline and test it / tweak it.
 
 ```js
-let booksFrom1996 = [
-    {$match: {year: 1996}},
+let justShowTitleSynopsis = [
     {$project: {title: 1, synopsis: 1}},
 ]
 
@@ -68,7 +67,7 @@ db.authors.aggregate([
        localField: "books",
        foreignField: "_id",
        pipeline:
-          booksFrom1996,
+          justShowTitleSynopsis,
        as: "booksWritten"
      } 
     }

docs/60-lookups/2-advanced-lookups.mdx

@@ -16,7 +16,7 @@ db.books.aggregate([
     // as a book can have many authors, we get one doc per book's author
     {$unwind: "$authors"},
     // remove some noisy fields
-    {$project: {vectorizedSynopsis: 0, attributes: 0, reviews: 0}}
+    {$project: {attributes: 0, reviews: 0}}
 ])
 ```
 - now, we need to get the authors'information. For that, we'll use `$lookup`, linking the `_id` in the `authors` collection with the `_id` we have in each book's `authors` array. But as we can see here, these have a different type: the ones inside our array are Strings, while the `author` collection `_id` are `ObjectId`.
@@ -37,7 +37,7 @@ db.books.aggregate([
     // convert it to an objectId
     {"$set":{"authorId":{"$toObjectId":"$authors._id"}}},
     // remove some noisy fields
-    {$project: {vectorizedSynopsis: 0, attributes: 0, reviews: 0}}
+    {$project: {attributes: 0, reviews: 0}}
 ])
 ```
 
@@ -60,7 +60,7 @@ db.books.aggregate([
      } 
     },
     // remove some noisy fields
-    {$project: {vectorizedSynopsis: 0, attributes: 0, reviews: 0}}
+    {$project: {attributes: 0, reviews: 0}}
 ])
 ```