update docs

Signed-off-by: annie_wangli <annie.wangli@huawei.com>

README.md

@@ -1,36 +1,63 @@
-# useriam_useridm
-
-#### Description
-{**When you're done, you can delete the content in this README and update the file with details for others getting started with your repository**}
-
-#### Software Architecture
-Software architecture description
-
-#### Installation
-
-1.  xxxx
-2.  xxxx
-3.  xxxx
-
-#### Instructions
-
-1.  xxxx
-2.  xxxx
-3.  xxxx
-
-#### Contribution
-
-1.  Fork the repository
-2.  Create Feat_xxx branch
-3.  Commit your code
-4.  Create Pull Request
+# User Identity Management (useridm)
 
 
-#### Gitee Feature
 
-1.  You can use Readme\_XXX.md to support different languages, such as Readme\_en.md, Readme\_zh.md
-2.  Gitee blog [blog.gitee.com](https://blog.gitee.com)
-3.  Explore open source project [https://gitee.com/explore](https://gitee.com/explore)
-4.  The most valuable open source project [GVP](https://gitee.com/gvp)
-5.  The manual of Gitee [https://gitee.com/help](https://gitee.com/help)
-6.  The most popular members  [https://gitee.com/gitee-stars/](https://gitee.com/gitee-stars/)
+## Introduction
+
+As a basic component of the Identity & Access Management (IAM) subsystem, User Identity Management (useridm) provides a unified interface for managing user credential information in the system and invokes authentication resources through the authentication executor management module to implement lifecycle management and secure storage of user credentials.
+
+**Figure 1 User identity credential management architecture
+
+<img src="figures/useridm_architecture.png" alt="useridm_architecture" style="zoom:80%;" />
+
+## Directory Structure
+
+```undefined
+//base/user_iam/user_idm
+├── frameworks			# Framework code
+├── interfaces			# Directory for storing external interfaces
+│   └── innerkits		# Header files exposed to the internal subsystem
+├── sa_profile			# Profile of the Service Ability
+├── services			# Implementation of Service Ability services
+├── unittest			# Directory for storing test code
+├── utils			    # Directory for storing utility code
+├── bundle.json			# Component description file
+└── useridm.gni			# Build configuration
+```
+
+
+## Usage
+
+### Available APIs
+
+**Table 1 ** APIs for managing user credentials
+
+| API | Description                            |
+| ------ | -------------------------------- |
+| addCredential(credentialInfo : CredentialInfo, callback : IIdmCallback) : void; | Adds a user credential.|
+| updateCredential(credentialInfo:CredentialInfo, callback:IIdmCallback) : void; | Updates a user credential.|
+| delUser(token : Uint8Array, callback : IIdmCallback) : void; | Deletes a user password. When a user password is deleted, all authentication credentials of the user are also deleted.|
+| delCred(credentialId : Uint8Array, token : Uint8Array, callback : IIdmCallback) : void; | Deletes a user credential.|
+
+**Table 2** API for querying user credential information
+
+| API| Description                      |
+| ------ | -------------------------------- |
+| getAuthInfo(callback : AsyncCallback<Array<EnrolledCredInfo>>,authType? : AuthType) : void; | Obtains one or all types of authentication credentials of a user.|
+
+### Usage Guidelines
+
+- The APIs defined in the header file ```common\interface\useridm_interface.h``` in the [useriam_auth_executor_mgr](https://gitee.com/openharmony-sig/useriam_coauth) repository must be implemented in a Trusted Execution Environment (TEE). In addition, the association between the user credentials and user IDs should not be tampered with, and unified user authentication must be supported.
+- During the adaptation, vendors can refer to the software implementation of related functions provided by the OpenHarmony framework.
+
+## Repositories Involved
+
+[useriam_auth_executor_mgr](https://gitee.com/openharmony-sig/useriam_coauth)
+
+**[useriam_user_idm](https://gitee.com/openharmony-sig/useriam_useridm)**
+
+[useriam_user_auth](https://gitee.com/openharmony-sig/useriam_userauth)
+
+[useriam_pin_auth](https://gitee.com/openharmony-sig/useriam_pinauth)
+
+[useriam_faceauth](https://gitee.com/openharmony/useriam_faceauth)