Merge pull request #67 from yassun7010/update_doc

Update doc

Author: ya7010

serde_valid/README.md

@@ -170,6 +170,10 @@ assert_eq!(
 
 ### Fluent localization
 
+<section class="warning">
+<code>fluent</code> feature is required.
+</section>
+
 You can also use [fluent](https://projectfluent.org/) localization by using `fluent` feature.
 
 ```rust

serde_valid/src/lib.rs

@@ -170,6 +170,10 @@
 //!
 //! ### Fluent localization
 //!
+//! <section class="warning">
+//! <code>fluent</code> feature is required.
+//! </section>
+//!
 //! You can also use [fluent](https://projectfluent.org/) localization by using `fluent` feature.
 //!
 //! ```rust