remove dead code

- mathjax.html: no page sets enableMathJax, and it was loading a
  useless polyfill along with some MathJax v2 code that never ran
- section.html: blog, speaking and writing have their own templates
- baseurl and figure shortcodes: no longer used

The generated site is identical.

Refs #11

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YNHsWYTXPThURz6TbVS1j3

layouts/_partials/head.html

@@ -86,10 +86,6 @@
 <script defer data-domain="itix.fr" src="https://plausible.io/js/plausible.js"></script>
 {{- end -}}
 
-{{- if .Params.enableMathJax -}}
-  {{- partial "mathjax.html" . -}}
-{{- end -}}
-
 <!-- Deal with the case of english articles published in the french site -->
 {{- partial "lang-detection.html" . -}}
 {{- if .Store.Get "en_article_in_fr_site" -}}

layouts/_partials/mathjax.html

@@ -1,36 +0,0 @@
-<!-- From https://note.qidong.name/2018/03/hugo-mathjax/ -->
-<script src="https://cdnjs.cloudflare.com/polyfill/v3/polyfill.min.js"></script>
-<script>
-MathJax = {
-  tex: {
-    inlineMath: [['$', '$'], ['\\(', '\\)']]
-  },
-  svg: {
-    fontCache: 'global'
-  }
-};
-</script>
-<script type="text/javascript" id="MathJax-script"
-async
-src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js">
-MathJax.Hub.Queue(function() {
-// Fix <code> tags after MathJax finishes running. This is a
-// hack to overcome a shortcoming of Markdown. Discussion at
-// https://github.com/mojombo/jekyll/issues/199
-var all = MathJax.Hub.getAllJax(), i;
-for(i = 0; i < all.length; i += 1) {
-all[i].SourceElement().parentNode.className += ' has-jax';
-}
-});
-</script>
-
-<style>
-code.has-jax {
-font: inherit;
-font-size: 100%;
-background: inherit;
-border: inherit;
-color: #515151;
-}
-</style>
-

layouts/_shortcodes/baseurl.html

@@ -1 +0,0 @@
-{{- .Page.Site.BaseURL -}}

layouts/_shortcodes/figure.html

@@ -1,10 +0,0 @@
-<!-- This shortcode renders an HTML figure based on a file dropped in the /public folder -->
-{{ $url := .Get "src" }}
-<figure>
-  <img src="{{ $url }}" alt="{{- .Get "title" | plainify -}}">
-  {{ with .Get "title" }}
-  <figcaption>
-    {{- . -}}
-  </figcaption>
-  {{ end }}
-</figure>

layouts/section.html

@@ -1,14 +0,0 @@
-{{ define "main" }}
-<!-- the section.html layout is used to render a list of articles under writing, speaking, etc. -->
-<article class="section">
-    <header>
-        <h1>{{ .Title }}</h1>
-    </header>
-    {{ .Content }}
-    <ul>
-        {{ range (sort .Pages "Date").Reverse }}
-            <li><a href="{{.RelPermalink}}">{{ .Title }}</a></li>
-        {{ end }}
-    </ul>
-</article>
-{{ end }}