BREAKING CHANGE(docs): Update documentation and examples to unify async and sync assertions, add custom matcher guides, and update package configuration

ts/namespaces/function.ts

@@ -0,0 +1,12 @@
+import { Assertion } from '../smartexpect.classes.assertion.js';
+
+/**
+ * Namespace for function-specific matchers
+ */
+export class FunctionMatchers {
+  constructor(private assertion: Assertion<Function>) {}
+
+  toThrow(expectedError?: any) {
+    return this.assertion.toThrow(expectedError);
+  }
+}