chore: add appdata file

linux/io.github.polypixeldev.Polypass.appdata.xml

@@ -0,0 +1,76 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<component type="desktop-application">
+  <id>io.github.polypixeldev.Polypass</id>
+
+  <name>Polypass</name>
+  <summary>A simple, secure, and easy to use password manager</summary>
+  <url type="homepage">https://github.com/polypixeldev/polypass</url>
+  <url type="bugtracker">https://github.com/polypixeldev/polypass/issues</url>
+
+  <metadata_license>MIT</metadata_license>
+  <project_license>GPL-3.0</project_license>
+  <developer_name>polypixeldev</developer_name>
+
+  <supports>
+    <control>pointing</control>
+    <control>keyboard</control>
+    <control>touch</control>
+  </supports>
+
+  <description>
+    <p>
+      Polypass is a simple, secure, and easy to use password manager
+    </p>
+  </description>
+
+  <launchable type="desktop-id">io.github.polypixeldev.Polypass.desktop</launchable>
+  <content_rating type="oars-1.0" />
+
+  <screenshots>
+    <screenshot type="default">
+      <caption>The home page</caption>
+      <image>https://raw.githubusercontent.com/polypixeldev/polypass/main/images/home.png</image>
+    </screenshot>
+    <screenshot>
+      <caption>The vault page</caption>
+      <image>https://raw.githubusercontent.com/polypixeldev/polypass/main/images/vault.png</image>
+    </screenshot>
+    <screenshot>
+      <caption>The generator page</caption>
+      <image>https://raw.githubusercontent.com/polypixeldev/polypass/main/images/generator.png</image>
+    </screenshot>
+  </screenshots>
+
+  <releases>
+    <release version="1.0.0" date="2022-08-03">
+      <description>
+        <p>
+          Initial release
+        </p>
+      </description>
+    </release>
+  </releases>
+  <release version="2.0.0" date="2023-03-12">
+    <description> Version 2.0.0 of PolyPass brings many big improvements to PolyPass, including: <ul>
+        <li>Android builds</li>
+        <li>Remote files via FTP</li>
+        <li>Offline access</li>
+        <li>Auto locking</li>
+        <li>Auto clipboard clearing</li>
+        <li>and more!</li>
+      </ul>
+
+    </description>
+  </release>
+  <release version="2.1.0" date="2023-05-07">
+    <description>
+      Unused release
+    </description>
+  </release>
+  <release version="2.2.0" date="2023-05-07">
+    <description>
+      Version 2.2.0 of Polypass adds Flatpak support and fixes capitalization of Polypass.
+      A tar.gz for Linux has been added.
+    </description>
+  </release>
+</component>