ESLint: add few docs for sonarjs

Author: cordis-dev

ESLint/sonarjs/prefer-read-only-props.md

@@ -0,0 +1,37 @@
+Pattern: Missing use of read-only prop
+
+Issue: -
+
+## Description
+
+React props should be read-only because it helps to enforce the principle of immutability in React functional components. By making props read-only, you ensure that the data passed from a parent component to a child component cannot be modified directly by the child component. This helps maintain a clear data flow and prevents unexpected side effects.
+
+Overall, enforcing read-only props in React helps improve code reliability, maintainability, and performance.
+
+Example of **incorrect** code:
+
+```ts
+interface Props {
+  name: string;
+}
+
+function Welcome(props: Props) { // Noncompliant: The component props are not read-only
+  return <div>Hello {props.name}</div>;
+}
+```
+
+Example of **correct** code:
+
+```ts
+interface Props {
+  name: string;
+}
+
+function Welcome(props: Readonly<Props>) {
+  return <div>Hello {props.name}</div>;
+}
+```
+
+## Further Reading
+
+* [prefer-read-only-props](https://sonarsource.github.io/rspec/#/rspec/S6759/javascript)

ESLint/sonarjs/prefer-regexp-exec.md

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+Pattern: Missing use of `RegExp.exec()`
+
+Issue: -
+
+## Description
+
+`String.match()` behaves the same way as `RegExp.exec()` when the regular expression does not include the global flag `g`. While they work the same, `RegExp.exec()` can be slightly faster than `String.match()`. Therefore, it should be preferred for better performance.
+
+
+Example of **incorrect** code:
+
+```ts
+'foo'.match(/bar/);
+```
+
+Example of **correct** code:
+
+```ts
+/bar/.exec('foo');
+```
+
+## Further Reading
+
+* [prefer-regexp-exec](https://sonarsource.github.io/rspec/#/rspec/S6594/javascript)