feat(error): Add validation error classes for YouTube ID and URL (#91)

- Introduced new error classes for more specific validation error handling:
  - `IDValidationError`: Represents errors for invalid YouTube video IDs during validation.
  - `URLValidationError`: Represents errors for invalid YouTube video URLs during validation.
  - `UnknownYouTubeDomainError`: Represents errors due to invalid or unknown YouTube domains.

- Updated the `error` module to export the new error classes.

These additions provide better error handling and clarity for validation-related operations.

Authored-by: Ryuu Mitsuki <[email protected]>

lib/error.js

@@ -19,6 +19,35 @@ const { isPlainObject } = require('./utils/type-utils');
  */
 class IDExtractorError extends Error {}
 
+/**
+ * @classdesc Represents an error that occurred when given
+ *            YouTube video ID is invalid during validation.
+ *
+ * @extends Error
+ * @global
+ * @since   2.0.0
+ */
+class IDValidationError extends Error {}
+
+/**
+ * @classdesc Represents an error that occurred when given
+ *            YouTube video URL is invalid during validation.
+ *
+ * @extends Error
+ * @global
+ * @since   2.0.0
+ */
+class URLValidationError extends Error {}
+
+/**
+ * @classdesc Represents an error that occurred due to invalid or unknown YouTube domain.
+ *
+ * @extends Error
+ * @global
+ * @since   2.0.0
+ */
+class UnknownYouTubeDomainError extends Error {}
+
 /**
  * @classdesc A class represents the error that occurred due to defining an unknown
  * option in the configuration object and may throw during configuration validation.
@@ -102,6 +131,9 @@ class GlobalConfigParserError extends Error {
 
 module.exports = {
   IDExtractorError,
+  IDValidationError,
+  URLValidationError,
+  UnknownYouTubeDomainError,
   UnknownOptionError,
   InvalidTypeError,
   GlobalConfigParserError