feat(glossary): provide basic term glossary (#869)

* feat(glossary): provide basic term glossary

Enabled a site-wide terminology glossary.

* Added the `term` shortcode displaying term definition.
* Added the /glossary page showing all term definitions.
* Enabled a simplistic search of term definitions.

* refactor(glossary): update glossary page links and add callout for Hugo support

- Removed the glossary entry from the menu and adjusted weights for subsequent items.
- Added informational callouts in the glossary documentation for multiple languages, directing users to the Hugo Glossary Quick Reference.
- Updated links in the glossary documentation to point to the correct pages.

* fix(glossary): update links to glossary page format across multiple languages

- Changed links in the glossary documentation to use Hugo's relref format for consistency.
- Updated links in Persian, Japanese, English, and Simplified Chinese glossary pages.

---------

Co-authored-by: Xin <5097752+imfing@users.noreply.github.com>
Co-authored-by: Xin <xin@imfing.com>

layouts/_shortcodes/term.html

@@ -0,0 +1,32 @@
+{{- /*
+Highlight a glossary term
+
+@param {string} entry Either the glossary abbreviation or the term.
+
+or
+
+@param {string} 0 Either the glossary abbreviation or the term.
+
+@example {{< term entry="MAC" >}}
+@example {{< term "MAC" >}}
+*/ -}}
+
+{{- $entry := .Get "entry" | default (.Get 0) -}}
+{{- $entryLower := lower $entry -}}
+{{- $match := dict -}}
+
+<!-- Go over the term data file - data/<lang>/termbase.yaml -->
+{{- range (index .Site.Data .Site.Language.Lang "termbase") -}}
+  {{- if or (eq (lower .abbr) $entryLower) (eq (lower .term) $entryLower) -}}
+    {{- $match = . -}}
+    {{- break -}}
+  {{- end -}}
+{{- end -}}
+
+{{- with $match }}
+  <abbr title="{{ .definition | plainify }}">
+    {{- $entry -}}
+  </abbr>
+{{- else }}
+  {{- $entry -}}
+{{- end }}