G-code syntax highlighting: register gcode grammar in code_note_highlight; add hljs-name/attr colors to theme

theme/blog_share_theme.css

@@ -1787,4 +1787,9 @@ html.theme-light .mermaid svg .cluster .nodeLabel,
 html.theme-light .mermaid svg .cluster-label text {
     fill: #556753 !important;
     color: #556753 !important;
-}
+}
+/* ---------- G-code / Zusatz-Scopes (name = G/M-Codes, attr = Parameter) ---------- */
+.hljs-name { color: #E1CE98; }
+.hljs-attr { color: #77838a; }
+html.theme-light .hljs-name { color: #4c6c94; }
+html.theme-light .hljs-attr { color: #556753; }