fix: allow dot name (#1024)

* allow dot name

* Create giant-years-flash.md

Author: juliusmarminge

.changeset/giant-years-flash.md

@@ -0,0 +1,5 @@
+---
+"create-t3-app": patch
+---
+
+fix: allow dot name in name prompt

cli/src/utils/validateAppName.ts

@@ -13,7 +13,7 @@ export const validateAppName = (input: string) => {
     appName = paths.slice(indexOfDelimiter).join("/");
   }
 
-  if (validationRegExp.test(appName ?? "")) {
+  if (input === "." || validationRegExp.test(appName ?? "")) {
     return true;
   } else {
     return "App name must consist of only lowercase alphanumeric characters, '-', and '_'";