CONFIG: Enable sphinx-tojupyter to have julia language config

Author: mmcky

lectures/_config.yml

@@ -41,6 +41,7 @@ sphinx:
       - "image/jpeg"
       - "text/markdown"
       - "text/plain"
+    highlight_language: julia
     html_favicon: _static/lectures-favicon.ico
     html_theme: quantecon_book_theme
     html_static_path: ['_static']
@@ -63,15 +64,16 @@ sphinx:
     mathjax_path: https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-svg.js
     rediraffe_redirects:
       index_toc.md: intro.md
+    tojupyter_default_lang: julia
+    tojupyter_lang_synonyms: ['julia-1.6']
     tojupyter_static_file_path: ["source/_static", "_static"]
     tojupyter_target_html: true
     tojupyter_urlpath: "https://julia.quantecon.org/"
     tojupyter_image_urlpath: "https://julia.quantecon.org/_static/"
     tojupyter_kernels:
       julia:
         kernelspec:
-          display_name: "Julia"
+          display_name: Julia
           language: julia
-          name: julia
-        file_extension: ".jl"
+          name: julia-1.6
     tojupyter_images_markdown: true