Implement hook_help()

This patch solves the task.

The first two sentences taken from the project page would be more correct.

Updated patch.

+      $output .= '<p>' . t('Maintenance IP Whitelist module you to set a whitelist of IP addresses that are allowed to bypass the maintenance mode of a website.') . '</p>';
+      $output .= '<p>' . t('This is particularly useful if, as an site administrator, you need to test specific workflows that are built for anonymous users and requires you to browse the website without being connected.') . '</p>';
+      $output .= '<p>' . t('Visit the <a href=":project_link">Project page</a> on Drupal.org for more information.', [

The first translatable text does not have the article for the subject and the verb.
The second translatable text is using the third singular person for a plural noun (workflows).
The third translatable text uses the capital case for a word that is not at the beginning of a sentence (Project).

+      $output .= '<p>' . t('This is particularly useful if a site administrator need to test specific workflows that are built for anonymous users and needs to browse the website without being connected.') . '</p>';

If and needs to browse the website without being connected is referred to workflows, needs is wrong. If instead and needs to browse the website without being connected is referred to a site administrator, needs is correct.

site administrator is singular, so need is wrong.

Kindly Review: Merge request !1

Patch is working and marking it to RTBC.

Resolved all the reviews provided on PR. Please review.

Verified the MR1 on 9.5.9 & help() is added. Added screenshots for reference & it can be moved to RTBC
Thank you.

There is no need to show that the hook_help() implementation is recognized by Drupal. As long as the hook implementation is using the correct name, Drupal will recognize that hook.