[nvim/nvim-lspconfig] Set LSP keymappings only in buffers with an active LSP.

.config/nvim/init.vim

@@ -1,7 +1,16 @@
 set runtimepath^=~/.vim runtimepath+=~/.vim/after
 let &packpath = &runtimepath
 source ~/.vimrc
+
 lua << EOF
+
+-- Set LSP keymappings in on_attach (i.e. only in buffers with LSP active)
+local on_attach = function(client, bufnr)
+    opts = { noremap=true, silent=true }
+    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'K', '<cmd>lua vim.lsp.buf.hover()<CR>', opts)
+end
+
+-- Julia LSP (LanguageServer.jl)
 require'lspconfig'.julials.setup({
     on_new_config = function(new_config, _)
         local julia = vim.fn.expand("~/.julia/environments/nvim-lspconfig/bin/julia")
@@ -15,6 +24,7 @@ require'lspconfig'.julials.setup({
         return util.root_pattern 'Project.toml'(fname) or util.find_git_ancestor(fname) or
                util.path.dirname(fname)
     end,
+    on_attach = on_attach,
 })
+
 EOF
-:nmap K :lua vim.lsp.buf.hover() <CR>