docs: add blank lines before code blocks for readability

fix: add deprecation warning for setup()

doc/cp.nvim.txt

@@ -206,6 +206,7 @@ Debug Builds ~
 CONFIGURATION                                                      *cp-config*
 
 Configuration is done via `vim.g.cp_config`. Set this before using the plugin:
+
 >lua
     vim.g.cp_config = {
       languages = {
@@ -273,6 +274,7 @@ By default, C++ (g++ with ISO C++17) and Python are preconfigured under
 the default; per-platform overrides can tweak 'extension' or 'commands'.
 
 For example, to run CodeForces contests with Python by default:
+
 >lua
     vim.g.cp_config = {
       platforms = {
@@ -282,8 +284,10 @@ For example, to run CodeForces contests with Python by default:
       },
     }
 <
+
 Any language is supported provided the proper configuration. For example, to
 run CSES problems with Rust using the single schema:
+
 >lua
     vim.g.cp_config = {
       languages = {

lua/cp/init.lua

@@ -34,4 +34,13 @@ function M.is_initialized()
   return initialized
 end
 
+---@deprecated Use `vim.g.cp_config` instead
+function M.setup(user_config)
+  vim.deprecate('require("cp").setup()', 'vim.g.cp_config', 'v0.1.0', 'cp.nvim', false)
+
+  if user_config then
+    vim.g.cp_config = vim.tbl_deep_extend('force', vim.g.cp_config or {}, user_config)
+  end
+end
+
 return M