Add introduction plugin (#127)

source/plugins/introduction/README.md

@@ -0,0 +1,26 @@
+### 🙋 Introduction
+
+The *introduction* plugin display your account bio or your organization/repository description.
+It is mostly intended for metrics used outside of GitHub, since these informations are already available on GitHub.
+
+<table>
+  <td align="center">
+    <img src="https://github.com/lowlighter/lowlighter/blob/master/metrics.plugin.introduction.svg">
+    <details><summary>Repository version</summary>
+      <img src="https://github.com/lowlighter/lowlighter/blob/master/metrics.plugin.introduction.repository.svg">
+    </details>
+    <img width="900" height="1" alt="">
+  </td>
+</table>
+
+#### ℹ️ Examples workflows
+
+[➡️ Available options for this plugin](metadata.yml)
+
+```yaml
+- uses: lowlighter/metrics@latest
+  with:
+    # ... other options
+    plugin_introduction: yes
+    plugin_introduction_title: no # Hide section title
+```