Add onboarding to connect repos without remotes

README.md

@@ -17,6 +17,9 @@ A single-file terminal UI for common Git workflows.
   - Initialize local repository
   - Optionally create and publish a new remote repository
   - Supports GitHub and Gitea
+- Existing local repo without remote:
+  - Offers connection to an existing GitHub or Gitea remote repository
+  - Can continue without remote setup if preferred
 
 ## Requirements
 
@@ -46,6 +49,11 @@ If the directory is not a Git repository, `git-tui` offers:
 - Initialize repository only
 - Initialize and publish to a new remote repository
 
+If the directory is already a Git repository but has no remote configured, `git-tui` offers:
+
+- Connect to an existing remote repository
+- Continue without remote
+
 ## Gitea Setup
 
 For Gitea publish flow, you can provide values interactively in the TUI or pre-set environment variables: