Update README

README.md

@@ -8,27 +8,34 @@ Generate valid Terraform configuration from state.
 go install github.com/magodo/tfadd@latest
 ```
 
-## Usage
+## Intro
 
 The goal of this tool is to improve the [import experience](https://learn.hashicorp.com/tutorials/terraform/state-import?in=terraform/state&utm_source=WEBSITE&utm_medium=WEB_IO&utm_offer=ARTICLE_PAGE&utm_content=DOCS) of Terraform, that rather than constructing the configurations from scratch, `tfadd` (try its best to) provide users a **valid** configuration automatically.
 
 > The **valid** here means the generated configuration should raise no error and show no diff during `terraform plan`. 
 
+Currently to generate the state, the tool supports *full mode* (with `-full`) or *partial mode* (by default).
+
+- In *full mode*, `tfadd` outputs all non-computed properties in the generated config. The generated config might be **invalid** for kinds of reasons, where manual modification is needed. But the benefit is that it works for any Terraform provider.
+- In *partial mode*, `tfadd` only outputs properties without `Optional+Computed` properties, with cross property constraints taken into consideration. This mode aims aims to generate a **valid** Terraform config. Currently, this mode can only works for the following providers:
+
+    |Name|Version|
+    |-|-|
+    |registry.terraform.io/hashicorp/aws|v4.17.1|
+    |registry.terraform.io/hashicorp/azurerm|v3.9.0|
+    |registry.terraform.io/hashicorp/google|v4.23.0|
+
+## Usage
+
 The typical usage is to use `tfadd` together with `terraform import`:
 
 1. Prepare an empty [workspace](https://www.terraform.io/language/state/workspaces) (e.g. an empty directory for *local* backend)
-1. (`tfadd` only) Run `tfadd init [providers...] > terraform.tf` to populate the Terraform setting to pin the provider version
+1. Identify the existing resources to import, write down the empty resource block
+1. (*partial mode* only) Run `tfadd init [providers...] > terraform.tf` to populate the Terraform setting to pin the provider version
 1. Run `terraform init` to initialize the providers
-1. Identify the existing resources to be managed via `terraform`, write down the empty resource block and import them via `terraform import`
-1. (`tfadd` only) Run `tfadd state` to generate the configuration
-
-Currently, the tool supports the following providers:
+1. Import the resources via `terraform import`
+1. Run `tfadd state` or `tfadd state -full` to generate the configuration
 
-|Name|Version|
-|-|-|
-|registry.terraform.io/hashicorp/aws|v4.17.1|
-|registry.terraform.io/hashicorp/azurerm|v3.9.0|
-|registry.terraform.io/hashicorp/google|v4.23.0|
 
 ## Limitation