Upgrade jni dependency

Update README

Author: vadage

Cargo.toml

@@ -10,7 +10,7 @@ name = "classloader"
 crate-type = ["cdylib"]
 
 [dependencies]
-jni = "0.20.0"
+jni = "0.21.1"
 retour = { version = "0.3.1", features = ["static-detour"] }
 winapi = { version = "0.3.9", features = ["libloaderapi"] }
 

README.md

@@ -1,12 +1,24 @@
-# How it works
+> Rust library for Java to decrypt classes on definition, utilising a hook in the JVM.
+
+# JVM ClassLoader hook
+
+## How it works
 This library enhances the JVM by creating a hook when loaded in the `JVM_DefineClassWithSource` export in the `jvm` library.<br>
 This feature gives us the ability to read and modify the bytes of a class before it's constructed, providing greater control and customization options.
 
-# Note
+## Note
 Please note that this is a basic implementation of class decryption in Java.<br>
 While this method may provide a first line of defense against immediate decompiling, it's important to understand that more advanced tools and agents may still be able to read and modify the loaded classes.<br>
 Keep this in mind as you use this feature in your projects.
 
+## Compatibility
+### ✅ Java
+All Java versions should be supported, as `jni` is only used for the structs and no method calls or such.<br>
+Thus far only `Java 8`, `Java 20` and `Java 21` were explicitly tested.
+
+### ⚠️ Operating system
+The build targets only windows, as the library heavily relies on functionality of `winapi`.
+
 # How to build
 1. [Install rust](https://www.rust-lang.org/tools/install)
 2. Install nightly by running `rustup install nightly`
@@ -37,7 +49,8 @@ for (int i = 0; i < classBytes.length; i++) {
 }
 ```
 
-### Override the javas magic value with your custom one
+### Override javas magic value with your custom one
+This allows the library to detect a custom class, to forward it to the decryption procedure.
 ```java
 System.arraycopy(CUSTOM_MAGIC_VALUE, 0, classBytes, 0, CUSTOM_MAGIC_VALUE.length);
 ```