Improve documentation and remove deprecate methods from Entity
>>> [!note] Migrated issue
<!-- Drupal.org comment -->
<!-- Migrated from issue #3530836. -->
Reported by: [liam morland](https://www.drupal.org/user/493050)
Related to !23
>>>
<h3 id="summary-problem-motivation">Problem/Motivation</h3>
<p>Some methods are documented with <code>{@inheritdoc}</code> when there is nothing to inherit from.</p>
<h3 id="summary-proposed-resolution">Proposed resolution</h3>
<p>Document these.</p>
<h3 id="summary-remaining-tasks">Remaining tasks</h3>
<p>Implement.</p>
<h3 id="summary-ui-changes">User interface changes</h3>
<p>None.</p>
<h3 id="summary-api-changes">API changes</h3>
<p>None.</p>
<h3 id="summary-data-model-changes">Data model changes</h3>
<p>None.</p>
issue