refactor: update icon implementation in footer, header, and languages partials

- Replace static SVG image paths with partials for icons in footer, header, and languages sections.
- Update alt text for icons to use internationalization support.
- Change header title from strong to h3 for better semantic structure.

Author: pseudoyu

layouts/partials/docs/footer.html

@@ -5,7 +5,7 @@
     {{- $date := partial "docs/date" (dict "Date" .GitInfo.AuthorDate.Local "Format" .Site.Params.BookDateFormat) -}}
     {{- $commitPath := default "commit" .Site.Params.BookCommitPath -}}
     <a class="flex align-center" href="{{ .Site.Params.BookRepo }}/{{ $commitPath }}/{{ .GitInfo.Hash }}" title='{{ i18n "Last modified by" }} {{ .GitInfo.AuthorName }} | {{ $date }}' target="_blank" rel="noopener">
-      <img src="{{ "svg/calendar.svg" | relURL }}" class="book-icon" alt="Calendar" />
+      <img src="{{ partial "docs/icon" "calendar" }}" class="book-icon" alt="{{ partial "docs/text/i18n" "Calendar" }}" />
       <span>{{ $date }}</span>
     </a>
   </div>
@@ -14,7 +14,7 @@
 {{ if and .File .Site.Params.BookRepo .Site.Params.BookEditPath }}
   <div>
     <a class="flex align-center" href="{{ .Site.Params.BookRepo }}/{{ .Site.Params.BookEditPath }}/{{ .Site.Params.contentDir | default "content" }}/{{ replace .File.Path "\\" "/" }}" target="_blank" rel="noopener">
-      <img src="{{ "svg/edit.svg" | relURL }}" class="book-icon" alt="Edit" />
+      <img src="{{ partial "docs/icon" "edit" }}" class="book-icon" alt="{{ partial "docs/text/i18n" "Edit" }}" />
       <span>{{ i18n "Edit this page" }}</span>
     </a>
   </div>

layouts/partials/docs/header.html

@@ -1,13 +1,13 @@
 <div class="flex align-center justify-between">
   <label for="menu-control">
-    <img src="{{ "svg/menu.svg" | relURL }}" class="book-icon" alt="Menu" />
+    <img src="{{ partial "docs/icon" "menu" }}" class="book-icon" alt="{{ partial "docs/text/i18n" "Menu" }}" />
   </label>
 
-  <strong>{{ partial "docs/title" . }}</strong>
+  <h3>{{ partial "docs/title" . }}</h3>
 
   <label for="toc-control">
-    {{ if default true (default .Site.Params.BookToC .Params.BookToC) }}
-    <img src="{{ "svg/toc.svg" | relURL }}" class="book-icon" alt="Table of Contents" />
+    {{ if partial "docs/toc-show" . }}
+    <img src="{{ partial "docs/icon" "toc" }}" class="book-icon" alt="{{ partial "docs/text/i18n" "Table of Contents" }}" />
     {{ end }}
   </label>
 </div>

layouts/partials/docs/languages.html

@@ -15,7 +15,7 @@
     <input type="checkbox" id="languages" class="toggle" />
     <label for="languages" class="flex justify-between">
       <a role="button" class="flex align-center">
-        <img src="{{ "svg/translate.svg" | relURL }}" class="book-icon" alt="Languages" />
+        <img src="{{ partial "docs/icon" "translate" }}" class="book-icon" alt="{{ partial "docs/text/i18n" "Languages" }}" />
         {{ $.Site.Language.LanguageName }}
       </a>
     </label>