Update README.md

Author: JessYanCoding

README-zh.md

@@ -114,7 +114,7 @@
 * 如果您在 **layout** 文件中使用 **mm** 作为单位进行布局 (需要通过 **AutoSizeConfig.getInstance().getUnitsManager().setSupportSubunits(Subunits.MM);** 打开对单位 **mm** 的支持)，则可以根据公式 **(sqrt(纵向分辨率^2+横向分辨率^2))/25.4** 求出屏幕尺寸，然后创建模拟设备 (**只用填写屏幕尺寸和分辨率**)
 ![mm](art/unit_mm.png)
 
-## Advanced (以下用法看不懂？答应我，认真看 Demo 好不好？)
+## Advanced (以下用法看不懂？答应我，认真看 demo 好不好？)
 
 ### Activity
 * **当某个 Activity 的设计图尺寸与在 AndroidManifest 中填写的全局设计图尺寸不同时，可以实现 CustomAdapt 接口扩展适配参数**

README.md

@@ -75,8 +75,8 @@
  implementation 'me.jessyan:autosize:0.9.1'
 ```
 
-## Usage (just one steps)
-### Step 1 
+## Usage
+### Step 1 (just one steps) 
 * **Initialize in AndroidManifest:**
 ```xml
 <manifest>
@@ -108,15 +108,13 @@ public class CustomAdaptActivity extends AppCompatActivity implements CustomAdap
         return 667;
     }
 }
-
 ```
 
 * **Cancel the adaptation of the Activity:**
 ```java
 public class CancelAdaptActivity extends AppCompatActivity implements CancelAdapt {
 
 }
-
 ```
 
 ### Fragment
@@ -139,15 +137,24 @@ public class CustomAdaptFragment extends Fragment implements CustomAdapt {
         return 667;
     }
 }
-
 ```
 
 * **Cancel the adaptation of the Fragment:**
 ```java
 public class CancelAdaptFragment extends Fragment implements CancelAdapt {
 
 }
+```
 
+### Subunits (see demo-subunits)
+* You can choose one of the three unpopular units of **pt, in, mm** as the subunits, the subunits is used to avoid the adverse effects caused by modifying **DisplayMetrics#density**, after using the subunits, you can write the pixel size on the design, you don't need to convert it to **dp**
+
+
+```java
+AutoSizeConfig.getInstance().getUnitsManager()
+        .setSupportDP(false)
+        .setSupportSP(false)
+        .setSupportSubunits(Subunits.MM);
 ```
 
 ## ProGuard