fix(jonathandarker): add highlights for diagnostics

.config/nvim/custom/jonathandarker/lua/jonathandarker/colors/default.lua

@@ -57,6 +57,21 @@ return {
         p.link("Ignore", "Normal")
 
         p.hset("Error", { fg = p.RED })
+        p.hset("DiagnosticError", { fg = p.RED })
+        p.hset("DiagnosticWarn", { fg = p.ORANGE })
+        p.hset("DiagnosticInfo", { fg = p.BACKGROUNDALT })
+        p.hset("DiagnosticHint", { fg = p.YELLOW })
+        p.hset("DiagnosticVirtualTextError", { underline = true, sp = p.RED })
+        p.hset("DiagnosticVirtualTextWarn", { underline = true, sp = p.ORANGE })
+        p.hset("DiagnosticVirtualTextInfo",
+            { underline = true, sp = p.BACKGROUNDALT })
+        p.hset("DiagnosticVirtualTextHint", { underline = true, sp = p.YELLOW })
+        p.hset("DiagnosticUnderlineError", { underline = true, sp = p.RED })
+        p.hset("DiagnosticUnderlineWarn", { underline = true, sp = p.ORANGE })
+        p.hset("DiagnosticUnderlineInfo",
+            { underline = true, sp = p.BACKGROUNDALT })
+        p.hset("DiagnosticUnderlineHint", { underline = true, sp = p.YELLOW })
+
 
         p.hset("Todo", { fg = p.TODO_COMMENT })