feat(snacks.picker): added support for Project shortcuts in other dashboards (#5607)

…shboard-nvim, and mini-starter

## Description

Though the snacks.picker extra provides a project picker, it only adds
the 'Projects' shortcut to snacks' dashboard, and no to the other three
dashboard extra: alpha, dashboard-nvim and mini-starter. In this PR, I
added the 'Projects' shortcuts to these three dashboard extras.

<!-- Describe the big picture of your changes to communicate to the
maintainers
  why we should accept this pull request. -->

## Related Issue(s)

<!--
  If this PR fixes any issues, please link to the issue here.
  - Fixes #<issue_number>
-->

- Fixes #5465

## Screenshots

<!-- Add screenshots of the changes if applicable. -->

alpha


![image](https://github.com/user-attachments/assets/c050f260-8602-4660-a386-62ab8400ef87)

dashboard-nvim


![image](https://github.com/user-attachments/assets/8973cd62-ba97-4330-9462-74163b58dca9)

mini.starter


![image](https://github.com/user-attachments/assets/a31ec27d-7efb-4aa3-a136-2a4ffedf5ba1)

## Checklist

- [x] I've read the
[CONTRIBUTING](https://github.com/LazyVim/LazyVim/blob/main/CONTRIBUTING.md)
guidelines.

lua/lazyvim/plugins/xtras.lua

@@ -11,6 +11,9 @@ local prios = {
   -- default priority is 50
   ["lazyvim.plugins.extras.editor.aerial"] = 100,
   ["lazyvim.plugins.extras.editor.outline"] = 100,
+  ["lazyvim.plugins.extras.ui.alpha"] = 19,
+  ["lazyvim.plugins.extras.ui.dashboard-nvim"] = 19,
+  ["lazyvim.plugins.extras.ui.mini-starter"] = 19,
 }
 
 if vim.g.xtras_prios then