added winblend option to blink.cmp, set to 0 for now

lua/plugins/blink.lua

@@ -25,6 +25,16 @@ return {
         completion = {
             documentation = {
                 auto_show = true,
+                winblend = 0,
+            },
+            menu = {
+                winblend = 0,
+            },
+        },
+
+        signature = {
+            window = {
+                winblend = 0,
             },
         },