fix: change url from lspconfig doc (#501)

Co-authored-by: Micha Reiser <micha@reiser.io>

README.md

@@ -83,7 +83,7 @@ To use `ruff-lsp` with Neovim, follow these steps:
 
 ```lua
 -- Configure `ruff-lsp`.
--- See: https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md#ruff_lsp
+-- See: https://github.com/neovim/nvim-lspconfig/blob/master/doc/configs.md#ruff_lsp
 -- For the default config, along with instructions on how to customize the settings
 require('lspconfig').ruff_lsp.setup {
   init_options = {