Correct some word errors and add a picture in readme. (Azure#32536)

* Update pic in Azure Identity Extensions.
Co-authored-by: Xiaolu Dai <[email protected]>

Author: backwind1233

sdk/identity/azure-identity-extensions/Azure-Database-for-MySQL-README.md

@@ -143,7 +143,7 @@ MySQL)[Azure Active Directory for authenticating with MySQL]
 
 ### Architecture
 
-This picture shows how the jdbc authentication plugin for MySQL authenticating with MSI.
+This picture shows how the jdbc authentication plugin for MySQL authenticating with managed identity.
 
 ![mysql_design.png](img/mysql_design.png)
 

sdk/identity/azure-identity-extensions/Azure-Database-for-PostgreSQL-README.md

@@ -145,13 +145,13 @@ PostgreSQL)[Use Azure Active Directory for authenticating with PostgreSQL]
 
 ### Architecture
 
-This picture shows how the jdbc authentication plugin for PostgreSQl authenticating with MSI.
+This picture shows how the jdbc authentication plugin for PostgreSQl authenticating with managed identity.
 
 ![postgresql_design.png](img/postgresql_design.png)
 
 1. The JDBC auth plugin will get an access token from Azure AD.
-2. The JDBC driver will take the token obtained from step 1 as the password ( `token as password`) to connect with the MySQL server.
-3. The MySQL server will check the access token and authenticate internally.
+2. The JDBC driver will take the token obtained from step 1 as the password ( `token as password`) to connect with the PostgreSQL server.
+3. The PostgreSQL server will check the access token and authenticate internally.
 
 ### Token as password
 

sdk/identity/azure-identity-extensions/README.md

@@ -2,6 +2,8 @@
   - [Getting started](#getting-started)
     - [Prerequisites](#prerequisites)
   - [Key concepts](#key-concepts)
+  - [Architecture](#architecture)
+    - [Authenticating with JDBC](#authenticating-with-jdbc)
   - [Examples](#examples)
   - [Troubleshooting](#troubleshooting)
   - [Next steps](#next-steps)
@@ -25,6 +27,13 @@ Azure Identity Extensions contains a common template framework for users to get
 use the token as a password. For example, to connect Azure hosted MySQL, get a token from Azure AD and use the
 token as a password to connect with MySQL.
 
+## Architecture
+
+### Authenticating with JDBC
+
+This picture shows how the JDBC authentication plugins provided by Azure Identity Extensions authenticate with managed identity.
+![Architecture](img/passwordless-connections-from-java-apps-to-data-services.jpg)
+
 ## Examples
 For documentation on how to use this package, please refer to [Quickstart:Use Java and JDBC with Azure Database for MySQL](https://aka.ms/passwordless/quickstart/mysql) and [Quickstart:Use Java and JDBC with Azure Database for PostgreSQL](https://aka.ms/passwordless/quickstart/postgresql).