fix(comment): add better comments in build_palette;

lua/nordic/colors/init.lua

@@ -5,8 +5,11 @@ local C = {}
 
 local function build_palette()
     -- make a new palette
+    -- copy the original palette, this overrides C
     C = vim.deepcopy(P)
+    -- because of the override, we need to re-add the build_palette
     C.build_palette = build_palette
+    -- that is also why it is not attached to C
 
     local options = require('nordic.config').options
 
@@ -102,5 +105,6 @@ end
 
 -- build the first palette
 build_palette()
+-- after this we can call it with C.build_palette()
 
 return C