fix docs and superfluous vim.validate calls

lua/cp/pickers/init.lua

@@ -108,7 +108,6 @@ function M.get_contests_for_platform(platform)
     })
   end
 
-  cache.set_contest_list(platform, contests)
   logger.log(('loaded %d contests'):format(#contests))
   return contests
 end

lua/cp/pickers/telescope.lua

@@ -47,7 +47,7 @@ local function contest_picker(opts, platform)
           end
         end)
 
-        map('i', '<C-r>', function()
+        map('i', '<c-r>', function()
           local cache = require('cp.cache')
           cache.clear_contest_list(platform)
           actions.close(prompt_bufnr)