gopls/doc: adjust nvim-lspconfig link target

The file was renamed in the github.com/neovim/nvim-lspconfig repository.

Change-Id: I89a8dcbbb31c24d77f0ca00934df1916b338d460
Reviewed-on: https://go-review.googlesource.com/c/tools/+/651195
Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Robert Findley <rfindley@google.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

Author: tklauser

gopls/doc/vim.md

@@ -230,5 +230,5 @@ require('lspconfig').gopls.setup({
 [govim-install]: https://github.com/myitcv/govim/blob/master/README.md#govim---go-development-plugin-for-vim8
 [nvim-docs]: https://neovim.io/doc/user/lsp.html
 [nvim-install]: https://github.com/neovim/neovim/wiki/Installing-Neovim
-[nvim-lspconfig]: https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md#gopls
+[nvim-lspconfig]: https://github.com/neovim/nvim-lspconfig/blob/master/doc/configs.md#gopls
 [nvim-lspconfig-imports]: https://github.com/neovim/nvim-lspconfig/issues/115