feat(jonathandarker): add markdown syntax highlighting rules

.config/nvim/custom/jonathandarker/lua/jonathandarker/colors/treesitter/init.lua

@@ -2,5 +2,6 @@ return {
     load = function(p)
         require("jonathandarker.colors.treesitter.default").load(p)
         require("jonathandarker.colors.treesitter.languages.python").load(p)
+        require("jonathandarker.colors.treesitter.languages.markdown").load(p)
     end
 }

.config/nvim/custom/jonathandarker/lua/jonathandarker/colors/treesitter/languages/markdown.lua

@@ -0,0 +1,14 @@
+return {
+    load = function(p)
+        p.hset("@markup.heading.1.markdown", { fg = p.ORANGE, bold = true })
+        p.hset("@markup.heading.2.markdown", { fg = p.ORANGE, bold = true })
+        p.hset("@markup.heading.3.markdown", { fg = p.YELLOW, bold = true })
+        p.hset("@markup.heading.4.markdown", { fg = p.YELLOW, bold = true })
+        p.hset("@markup.heading.5.markdown", { fg = p.YELLOW })
+        p.hset("@markup.heading.6.markdown", { fg = p.YELLOW })
+        p.hset("@markup.link.markdown_inline",
+            { fg = p.CYAN, underdashed = true })
+        p.hset("@markup.raw.markdown_inline",
+            { fg = p.BACKGROUND, bg = p.ORANGE })
+    end
+}