feat: Add support for JSON values

Author: fooker

Cargo.toml

@@ -13,7 +13,9 @@ keywords = ["fluent", "testing", "matchers", "assert", "assertions"]
 edition = "2021"
 
 [features]
-default = ["num"]
+default = ["num", "json"]
+json = ["dep:serde_json"]
 
 [dependencies]
 num = { version = "0.4.0", optional = true }
+serde_json = { version = "1.0.140", optional = true }