docs(NODE-2329): write upgrade and migration guide (#2890)

Co-authored-by: Eric Adum <[email protected]>
Co-authored-by: Daria Pardue <[email protected]>
Co-authored-by: Anna Henningsen <[email protected]>

Author: 4 people

README.md

@@ -2,17 +2,19 @@
 
 The official [MongoDB](https://www.mongodb.com/) driver for Node.js.
 
-**NOTE: v4.x was recently released with breaking API changes. You can find a list of changes [here](https://github.com/mongodb/node-mongodb-native/blob/4.0/HISTORY.md).**
+**Upgrading to version 4? Take a look at our [upgrade guide here](https://github.com/mongodb/node-mongodb-native/blob/4.0/docs/CHANGES_4.0.0.md)!**
 
 ## Quick Links
 
-| what          | where                                                                                                            |
-|---------------|------------------------------------------------------------------------------------------------------------------|
-| documentation | [https://docs.mongodb.com/drivers/node](https://docs.mongodb.com/drivers/node)                                   |
-| api-doc       | [https://mongodb.github.io/node-mongodb-native/4.0/](https://mongodb.github.io/node-mongodb-native/4.0/) |
-| npm package   | [https://www.npmjs.com/package/mongodb](https://www.npmjs.com/package/mongodb)                                   |
-| source        | [https://github.com/mongodb/node-mongodb-native](https://github.com/mongodb/node-mongodb-native)                 |
-| mongodb       | [https://www.mongodb.com](https://www.mongodb.com)                                                               |
+| what          | where                                                                                                  |
+| ------------- | ------------------------------------------------------------------------------------------------------ |
+| documentation | [docs.mongodb.com/drivers/node](https://docs.mongodb.com/drivers/node)                                 |
+| api-doc       | [mongodb.github.io/node-mongodb-native/4.0/](https://mongodb.github.io/node-mongodb-native/4.0/)       |
+| npm package   | [www.npmjs.com/package/mongodb](https://www.npmjs.com/package/mongodb)                                 |
+| source        | [github.com/mongodb/node-mongodb-native](https://github.com/mongodb/node-mongodb-native)               |
+| mongodb       | [www.mongodb.com](https://www.mongodb.com)                                                             |
+| changelog     | [HISTORY.md](https://github.com/mongodb/node-mongodb-native/blob/4.0/docs/HISTORY.md)                  |
+| upgrade to v4 | [docs/CHANGES_4.0.0.md](https://github.com/mongodb/node-mongodb-native/blob/4.0/docs/CHANGES_4.0.0.md) |
 
 ### Bugs / Feature Requests
 
@@ -103,7 +105,7 @@ For complete MongoDB installation instructions, see [the manual](https://docs.mo
 
 1. Download the right MongoDB version from [MongoDB](https://www.mongodb.org/downloads)
 2. Create a database directory (in this case under **/data**).
-3. Install and start a ``mongod`` process.
+3. Install and start a `mongod` process.
 
 ```bash
 mongod --dbpath=/data
@@ -194,7 +196,7 @@ const filteredDocs = await collection.find({ a: 3 }).toArray()
 console.log('Found documents filtered by { a: 3 } =>', filteredDocs)
 ```
 
-Only the documents which match ``'a' : 3`` should be returned.
+Only the documents which match `'a' : 3` should be returned.
 
 ### Update a document
 
@@ -223,7 +225,7 @@ performance. The following function creates an index on the **a** field in the
 **documents** collection.
 
 ```js
-const indexName = await collection.createIndex({a: 1})
+const indexName = await collection.createIndex({ a: 1 })
 console.log('index name =', indexName)
 ```