Rename TSInjex to TSinjex and Add Jest Setup in README

Renamed all instances of 'TSInjex' to 'TSinjex' for consistency across the codebase, including interfaces, classes, and test files. Updated the version in `package.json` from 0.0.5 to 0.0.6. Added Jest setup example to the `README.md` to guide developers on initial configuration for testing.

src/decorators/Register.ts

@@ -1,4 +1,4 @@
-import { TSInjex } from '../TSInjex';
+import { TSinjex } from '../TSinjex';
 
 /**
  * A decorator to register a class in the DI (Dependency Injection) container.
@@ -20,7 +20,7 @@ export function Register<
 >(identifier: string, deprecated?: boolean) {
     return function (constructor: TargetType, ...args: unknown[]): void {
         // Get the instance of the DI container
-        const diContainer = TSInjex.getInstance();
+        const diContainer = TSinjex.getInstance();
 
         // Register the class in the DI container
         diContainer.register(identifier, constructor, deprecated);