message: fix(docs-infra): add guard to not render anchor link for private api
  This commit adds a guard that prevents rendering anchor links for
  private api's.
  Closes
  PR Close
diff: {%- macro renderHeritage(exportDoc) -%}
  {%- if exportDoc.extendsClauses.length %} extends {% for clause in exportDoc.extendsClauses -%}
  - <a class="code-anchor" href="{$ clause.doc.path $}">{$ clause.text $}</a>{% if not loop.last %}, {% endif -%}
  + {% if clause.doc.path %}<a class="code-anchor" href="{$ clause.doc.path $}">{$ clause.text $}</a>{% else %}{$ clause.text $}{% endif %}{% if not loop.last %}, {% endif -%}
  {% endfor %}{% endif %}
  {%- if exportDoc.implementsClauses.length %} implements {% for clause in exportDoc.implementsClauses -%}
  <a class="code-anchor" href="{$ clause.doc.path $}">{$ clause.text $}</a>{% if not loop.last %}, {% endif -%}
  