Update color definitions and spelling options

Refactor diagnostic colors for better visibility in
editor and plugin highlight groups. Add new spelling
options for enhanced functionality.

lua/settings.lua

@@ -48,6 +48,7 @@ vim.opt.pumblend = 0 -- No transparency
 
 -- Spelling
 vim.opt.spelllang = { "en_gb" }
+vim.opt.spelloptions = { "camel,noplainbuffer" }
 
 -- Search behavior
 vim.opt.ignorecase = true -- Case-insensitive search by default