docs: add gastaldi as a contributor for code, and maintenance (#2)

* docs: update README.md [skip ci]

* docs: create .all-contributorsrc [skip ci]

---------

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>

Author: allcontributors[bot]

.all-contributorsrc

@@ -0,0 +1,26 @@
+{
+  "files": [
+    "README.md"
+  ],
+  "imageSize": 100,
+  "commit": false,
+  "commitConvention": "angular",
+  "contributors": [
+    {
+      "login": "gastaldi",
+      "name": "George Gastaldi",
+      "avatar_url": "https://avatars.githubusercontent.com/u/54133?v=4",
+      "profile": "http://gastaldi.wordpress.com",
+      "contributions": [
+        "code",
+        "maintenance"
+      ]
+    }
+  ],
+  "contributorsPerLine": 7,
+  "skipCi": true,
+  "repoType": "github",
+  "repoHost": "https://github.com",
+  "projectName": "quarkus-poi",
+  "projectOwner": "quarkiverse"
+}

README.md

@@ -1,4 +1,7 @@
 # Quarkus extension for Apache POI
+<!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
+[![All Contributors](https://img.shields.io/badge/all_contributors-1-orange.svg?style=flat-square)](#contributors-)
+<!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 [![Version](https://img.shields.io/maven-central/v/io.quarkiverse.poi/quarkus-poi?logo=apache-maven&style=flat-square)](https://search.maven.org/artifact/io.quarkiverse.poi/quarkus-poi)
 
@@ -31,4 +34,25 @@ Include the following dependency in your pom.xml:
 This extension provides the following features:
 
 - Native image support
-- Support for Apache POI 5.2.3
+- Support for Apache POI 5.2.3
+## Contributors ✨
+
+Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/docs/en/emoji-key)):
+
+<!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section -->
+<!-- prettier-ignore-start -->
+<!-- markdownlint-disable -->
+<table>
+  <tbody>
+    <tr>
+      <td align="center" valign="top" width="14.28%"><a href="http://gastaldi.wordpress.com"><img src="https://avatars.githubusercontent.com/u/54133?v=4?s=100" width="100px;" alt="George Gastaldi"/><br /><sub><b>George Gastaldi</b></sub></a><br /><a href="https://github.com/quarkiverse/quarkus-poi/commits?author=gastaldi" title="Code">💻</a> <a href="#maintenance-gastaldi" title="Maintenance">🚧</a></td>
+    </tr>
+  </tbody>
+</table>
+
+<!-- markdownlint-restore -->
+<!-- prettier-ignore-end -->
+
+<!-- ALL-CONTRIBUTORS-LIST:END -->
+
+This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification. Contributions of any kind welcome!