feat(lsp): completion side effects

runtime/lua/vim/lsp/protocol.lua

@@ -738,14 +738,16 @@ function protocol.make_client_capabilities()
       completion = {
         dynamicRegistration = false,
         completionItem = {
-          -- Until we can actually expand snippet, move cursor and allow for true snippet experience,
-          -- this should be disabled out of the box.
-          -- However, users can turn this back on if they have a snippet plugin.
-          snippetSupport = false,
+          snippetSupport = true,
           commitCharactersSupport = false,
           preselectSupport = false,
           deprecatedSupport = false,
           documentationFormat = { constants.MarkupKind.Markdown, constants.MarkupKind.PlainText },
+          resolveSupport = {
+            properties = {
+              'additionalTextEdits',
+            },
+          },
         },
         completionItemKind = {
           valueSet = get_value_set(constants.CompletionItemKind),