Move lsp/diagnostic UI config to separate file

lua/plugins/completions.lua

@@ -128,20 +128,6 @@ return {
     })
     require("cmp_git").setup({})
 
-    -- Customise LSP UI
-    vim.lsp.handlers['textDocument/hover'] = vim.lsp.with(
-      vim.lsp.handlers.hover, {
-        border = 'rounded',
-        title = 'Hover',
-      }
-    )
-    vim.lsp.handlers['textDocument/signatureHelp'] = vim.lsp.with(
-      vim.lsp.handlers.signature_help, {
-        border = 'rounded',
-        title = 'Signature Help',
-      }
-    )
-
     -- Mappings created when LSP is attached to a buffer
     local augroup = vim.api.nvim_create_augroup('lsp', { clear = true })
     vim.api.nvim_create_autocmd('LspAttach', {