Docs: update docs about init_wfc (#5912)

Author: YuLiu98

docs/advanced/input_files/input-main.md

@@ -583,7 +583,7 @@ These variables are used to control general system parameters.
 ### init_wfc
 
 - **Type**: String
-- **Description**: Only useful for plane wave basis only now. It is the name of the starting wave functions. In the future. we should also make this variable available for localized orbitals set.
+- **Description**: The type of the starting wave functions.
 
   Available options are:
 
@@ -593,6 +593,8 @@ These variables are used to control general system parameters.
   - random: random numbers
   - nao: from numerical atomic orbitals. If they are not enough, other wave functions are initialized with random numbers.
   - nao+random: add small random numbers on numerical atomic orbitals
+  
+  > Only the `file` option is useful for the lcao basis set, which is mostly used when [calculation](#calculation) is set to `set_wf` and `get_pchg`. See more details in [out_wfc_lcao](#out_wfc_lcao).
 - **Default**: atomic
 
 ### init_chg