options-state.md typo (#1550)

explicit declared -> explicitly declared

Author: SquidwardHill

src/api/options-state.md

@@ -78,7 +78,7 @@ Declare the props of a component.
 
 - **Details**
 
-  In Vue, all component props need to be explicit declared. Component props can be declared in two forms:
+  In Vue, all component props need to be explicitly declared. Component props can be declared in two forms:
 
   - Simple form using an array of strings
   - Full form using an object where each property key is the name of the prop, and the value is the prop's type (a constructor function) or advanced options.