Got Null-LS working with markdown and python.

lua/plugins/todo-comments.lua

@@ -0,0 +1,29 @@
+local g = vim.g
+
+require('todo-comments').setup {
+   keywords = {
+      FIX = {
+        icon = " ", -- icon used for the sign, and in search results
+        color = "error", -- can be a hex color, or a named color (see below)
+        alt = { "FIXME", "BUG", "FIXIT", "ISSUE" }, -- a set of other keywords that all map to this FIX keywords
+      -- signs = false, -- configure signs for some keywords individually
+      },
+      DONE = { icon = " ", color = "info" },
+      FEAT = { icon = " ", color = "warning", alt = { "NEED", "REQUEST" } },
+      WARN = { icon = " ", color = "error", alt = { "WARNING", "ERROR" } },
+      TASK = { icon = " ", color = "hint", alt = { "TODO", "TBD" } },
+      NOTE = { icon = " ", color = "hint", alt = { "INFO" } },
+      SENG = { icon = " ", color = "test", alt = { "SOLUTIONS", "SE", "WORKAROUND" } },
+    },
+    highlight = {
+      comments_only = false,
+    },
+    colors = {
+      error = { "DiagnosticError", "ErrorMsg", "#DC2626" },
+      warning = { "DiagnosticWarning", "WarningMsg", "#FBBF24" },
+      info = { "DiagnosticInfo", "#2563EB" },
+      hint = { "DiagnosticHint", "#10B981" },
+      default = { "Identifier", "#7C3AED" },
+      test = { "Identifier", "#FF00FF" }
+    },
+}