Refactor DI container for better structure and clarity

- Moved `TSinjex` class to `classes` directory for better organization.
- Updated imports across the codebase to reflect the new location of `TSinjex`.
- Introduced `Identifier` type to standardize dependency identifiers.
- Enhanced JSDoc comments for improved clarity and consistency.
- Adjusted error messages for `DependencyResolutionError` to provide clearer information.
- Updated and expanded decorator and function types to use `Identifier` type.

src/decorators/Inject.ts

@@ -1,18 +1,19 @@
-import { TSinjex } from '../TSinjex';
+import { Identifier } from 'src/types/Identifier';
+import { TSinjex } from '../classes/TSinjex';
 import { InitDelegate } from '../types/InitDelegate';
 
 /**
- * A decorator to inject a dependency from a DI (Dependency Injection) container.
- * The dependency is lazily evaluated when the property is accessed for the first time.
- * This can help avoid issues like circular dependencies and not-found dependencies.
- * @template ClassType The type of the property to be injected.
- * @param identifier The identifier used to resolve the dependency from the DI container.
+ * A decorator to inject a dependency from a DI (Dependency Injection) container into a class property.
+ * @template T The type of the dependency to be injected.
+ * @template U The type of the property to be injected.
+ * @param identifier The identifier used to resolve the class in the DI container.
+ * @see {@link Identifier} for more information on identifiers.
  * @param init An optional initializer function to transform the dependency before injection.
- * @param necessary Indicates if the dependency is necessary.
- * - If `true`, an error will be thrown if the dependency cannot be resolved.
- * - If `false`, `undefined` will be returned if the dependency cannot be resolved.
- * @returns A decorator function to be applied on the class property.
- * @see {@link TSinjex}
+ * @see {@link InitDelegate} for more information on initializer functions.
+ * @param necessary If true, throws an error if the dependency is not found.
+ * @returns The resolved dependency or undefined if the dependency is not necessary
+ * and not found, or throws an error if the dependency is necessary and not found.
+ * @throws A {@link DependencyResolutionError} if the dependency is not found and necessary.
  * @example
  * ```ts
  * class MyClass {
@@ -29,7 +30,7 @@ import { InitDelegate } from '../types/InitDelegate';
  * ```
  */
 export function Inject<T, U>(
-    identifier: string,
+    identifier: Identifier,
     init?: InitDelegate<T, U>,
     necessary = true,
 ) {

src/decorators/Register.ts

@@ -1,12 +1,14 @@
-import { TSinjex } from '../TSinjex';
+import { Identifier } from 'src/types/Identifier';
+import { TSinjex } from '../classes/TSinjex';
 
 /**
- * A decorator to register a class in the DI (Dependency Injection) container.
+ * A decorator to register a class in the **TSinjex** DI (Dependency Injection) container.
  * @template TargetType The type of the class to be registered.
  * @param identifier The identifier used to register the class in the DI container.
- * @param deprecated If true, the dependency is deprecated => a warning
- * is logged when the dependency is resolved.
- * @returns A function that is applied as a decorator to the class.
+ * @see {@link Identifier} for more information on identifiers.
+ * @param deprecated If true, the dependency is deprecated and a warning
+ * is logged only once upon the first resolution of the dependency.
+ * @returns The decorator function to be applied on the class.
  * @example
  * ```ts
  * \@Register('MyClassIdentifier')
@@ -17,7 +19,7 @@ import { TSinjex } from '../TSinjex';
  */
 export function Register<
     TargetType extends new (...args: unknown[]) => InstanceType<TargetType>,
->(identifier: string, deprecated?: boolean) {
+>(identifier: Identifier, deprecated?: boolean) {
     return function (constructor: TargetType, ...args: unknown[]): void {
         // Get the instance of the DI container
         const diContainer = TSinjex.getInstance();

src/decorators/RegisterInstance.ts

@@ -1,17 +1,19 @@
-import { TSinjex } from '../TSinjex';
+import { Identifier } from 'src/types/Identifier';
+import { TSinjex } from '../classes/TSinjex';
 import { InitDelegate } from '../types/InitDelegate';
 
 /**
  * A decorator to register an instance of a class in the DI (Dependency Injection) container.
- * The instance is created only when it is first needed (Lazy Initialization).
  * @template TargetType The type of the class whose instance is to be registered.
  * @param identifier The identifier used to register the instance in the DI container.
+ * @see {@link Identifier} for more information on identifiers.
  * @param init An optional initializer function which get the constructor of the class
  * as input and returns an instance of the class.
- * @returns A function that is applied as a decorator to the class.
+ * @see {@link InitDelegate} for more information on initializer functions.
+ * @returns The decorator function to be applied on the class.
  * @example
  * ```ts
- * \@RegisterInstance('MyClassInstanceIdentifier', arg1, arg2)
+ * \@RegisterInstance('MyClassInstanceIdentifier', (constructor) => new constructor())
  * class MyClass {
  *   // ...
  * }
@@ -20,7 +22,7 @@ import { InitDelegate } from '../types/InitDelegate';
 export function RegisterInstance<
     TargetType extends new (..._args: unknown[]) => InstanceType<TargetType>,
 >(
-    identifier: string,
+    identifier: Identifier,
     init?: InitDelegate<
         TargetType & { new (..._args: unknown[]): InstanceType<TargetType> },
         InstanceType<TargetType>