Add BibTeX citation box (#1325)

Implemented a citation box in BibTeX format as per the discussion in issue #1325. Details: #1325

Author: nrllh

src/static/css/page.css

@@ -292,6 +292,7 @@
 }
 
 .authors,
+.citation-box h2,
 .authors h2,
 .chapter-links,
 .chapter-links h2,
@@ -382,6 +383,20 @@
   margin-right: 0.25rem;
 }
 
+.citation-box pre {
+  padding: 16px;
+  border: 1px solid #e0e0e0;
+  border-radius: 4px;
+  background-color: #ffffff;
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
+  margin-bottom: 20px;
+  font-family: monospace;
+  background-color: #f9f9f9;
+  overflow-x: auto;
+  white-space: pre-wrap; /* Allow wrapping of long lines */
+  margin: 0;
+}
+
 #chapter-navigation {
   padding: 16px 36px 50px 36px;
   padding: 1rem 2.25rem 3.125rem 2.25rem;

src/templates/base/base_chapter.html

@@ -318,6 +318,31 @@ <h2 id="authors">
 </ul>
 {% endmacro %}
 
+{% macro render_bibtex() %}
+<h2 id="cite">
+  <a href="#cite" class="anchor-link">BibTeX</a>
+</h2>
+    <pre id="bibtex-citation">
+@inbook{WebAlmanac.{{ year }}.{{ metadata.get('title').replace(' ', '') }},
+author = "{% for author in metadata.get('authors') -%}
+  {%- set authordata = config.contributors.get(author, None) -%}
+  {%- if authordata %}
+    {%- set full_name = authordata.name.split(' ') -%}
+    {{ full_name[-1] }}, {{ full_name[0] }}{% if full_name|length > 2 %} {{ full_name[1:-1]|join(' ') }}{% endif %}{% if not loop.last %} and {% endif %}
+  {%- else %}
+    {%- set full_name = author.split(' ') -%}
+    {{ full_name[-1] }}, {{ full_name[0] }}{% if full_name|length > 2 %} {{ full_name[1:-1]|join(' ') }}{% endif %}{% if not loop.last %} and {% endif %}
+  {%- endif %}
+{%- endfor %}", 
+title = "{{ metadata.get('title') }}",
+booktitle = "The {{ year }} Web Almanac",
+chapter = {{ chapter_config.chapter_number }},
+publisher = "HTTP Archive",
+year = "{{ year }}",
+url = "https://almanac.httparchive.org/en/{{ year }}/{{ metadata.get('chapter') }}"
+}</pre>
+{% endmacro %}
+
 {% macro render_prevnext() %}
   {% if prev_chapter %}
     {% if chapter_lang_exists(lang, year, prev_chapter['slug']) %}
@@ -423,6 +448,8 @@ <h1 class="title title-lg">
         {% endif %}
         <section class="authors">
             {{ render_authors() }}
+        </section><section class="citation-box">
+            {{ render_bibtex() }} 
         </section>
         <div id="cta-container" class="invisible">
           {% if metadata.get('discuss') %}