docs: Update version in README.md

Author: Stranger6667

README.md

@@ -35,7 +35,7 @@ Will be turned into this:
 To use it in your project add the following line to your `dependencies` section in the project's `Cargo.toml` file:
 
 ```toml
-css-inline = "0.7"
+css-inline = "0.8"
 ```
 
 Minimum Supported Rust Version is 1.54.