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

ts/namespaces/string.ts

@@ -0,0 +1,32 @@
+import { Assertion } from '../smartexpect.classes.assertion.js';
+
+/**
+ * Namespace for string-specific matchers
+ */
+export class StringMatchers {
+  constructor(private assertion: Assertion<string>) {}
+
+  toStartWith(prefix: string) {
+    return this.assertion.toStartWith(prefix);
+  }
+
+  toEndWith(suffix: string) {
+    return this.assertion.toEndWith(suffix);
+  }
+
+  toInclude(substring: string) {
+    return this.assertion.toInclude(substring);
+  }
+
+  toMatch(regex: RegExp) {
+    return this.assertion.toMatch(regex);
+  }
+
+  toBeOneOf(values: string[]) {
+    return this.assertion.toBeOneOf(values);
+  }
+  /** Length check for strings */
+  toHaveLength(length: number) {
+    return this.assertion.toHaveLength(length);
+  }
+}