feat(rust): add rustaceanvim config

lua/config/plugins/rustaceanvim.lua

@@ -0,0 +1,18 @@
+local navic = require("nvim-navic")
+
+vim.g.rustaceanvim = {
+  server = {
+    on_attach = function(client, bufnr)
+        navic.attach(client, bufnr)
+    end,
+    filetypes = {"rust"},
+    settings = {
+      -- rust-analyzer language server configuration
+      ['rust-analyzer'] = {
+        cargo = {
+          allFeatures = true,
+        },
+      },
+    },
+  },
+}