[Feature]: Add documentation about new helpers and methods

### 🚀 Feature Proposal

## New helpers

- `Macroable`
- `Sleep`
- `Otp`

## New methods

### Is

- Add new `Is.Ulid()` method.
- Add new `Is.CssPath()` method.
- Add new `Is.ValidHash() method.

### String

- Add new `String.hash()` method.
- Add new `String.random()` method.

### Parser

- Add new `Parser.jsonToHTML()` method.

## Deprecations

### String

- Deprecate `String.generateRandom()` -> Use `String.random()` instead.

### Exec

- Deprecate `Exec.sleep()` method -> Use `Sleep` helper.
- Deprecate `Exec.concurrently()` method -> Use global `concurrently()` method present in `athenna` helper of arrays (`[].athenna.concurrently()`).

### Motivation

Improve helpers documentation.

### Example

_No response_

Start by reviewing the existing documentation structure for helpers and methods, then map the listed Macroable, Sleep, Otp, Is, String, Parser, and Exec items to their current entries. Done means documenting every listed addition and deprecation, including the replacement names and methods; the issue names no files or tests to run.

Written by the indexing model from the issue text.