feat: support linux build appimage

.gitignore

@@ -129,3 +129,7 @@ docs/wireframe.assets/*.excalidraw.svg
 docs/wireframe.assets/*.svg
 docs/wireframe.assets/*.png
 node_modules/
+AppDir/.DirIcon
+AppDir/bundle/
+appimage-build/
+/*.AppImage

AppDir/AppRun

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+export LD_LIBRARY_PATH="${APPDIR}/bundle/lib"
+exec $APPDIR/bundle/pdf_signature "$@"
+

AppDir/pdf_signature-icon.svg

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<!-- Uploaded to: SVG Repo, www.svgrepo.com, Generator: SVG Repo Mixer Tools -->
+<svg version="1.1" id="_x32_" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" 
+	 viewBox="0 0 512 512"  xml:space="preserve">
+<style type="text/css">
+	.st0{fill:#000000;}
+</style>
+<g>
+	<path class="st0" d="M56.007,114.35c-5.535-5.539-14.51-5.539-20.045,0L4.148,146.159c-5.531,5.539-5.531,14.506,0,20.046
+		l20.622,20.621l51.859-51.855L56.007,114.35z"/>
+	<polygon class="st0" points="286.422,396.623 268.742,327.077 216.884,378.94 	"/>
+	<path class="st0" d="M258.136,316.475L86.058,144.397L34.2,196.26l172.073,172.077L258.136,316.475z M87.468,166.56
+		l149.919,149.922l-11.784,11.78L75.684,178.348L87.468,166.56z"/>
+	<rect x="195.662" y="132.491" class="st0" width="29.356" height="28.017"/>
+	<rect x="195.662" y="200.693" class="st0" width="29.356" height="28.009"/>
+	<rect x="256.69" y="132.491" class="st0" width="173.056" height="28.017"/>
+	<rect x="256.69" y="200.693" class="st0" width="173.056" height="28.009"/>
+	<rect x="288.598" y="268.894" class="st0" width="141.148" height="28.01"/>
+	<path class="st0" d="M429.817,11.059H195.582c-45.32,0-82.182,36.858-82.182,82.179v32.726l30.427,30.435V93.238
+		c0-28.586,23.178-51.752,51.755-51.752h234.235c28.594,0,51.756,23.166,51.756,51.752v254.042h-80.097
+		c-23.822,0-43.124,19.318-43.124,43.132v80.101h-162.77c-28.578,0-51.755-23.166-51.755-51.752v-37.072l-6.234-1.587l6.234-6.235
+		v-22.202L113.4,321.239v97.522c0,45.313,36.862,82.179,82.182,82.179h162.77h12.598l8.917-8.913l123.224-123.224l8.909-8.912
+		v-12.61V93.238C512,47.917,475.138,11.059,429.817,11.059z"/>
+</g>
+</svg>

AppDir/pdf_signature.desktop

@@ -0,0 +1,7 @@
+[Desktop Entry]
+Version=1.0
+Type=Application
+Name=pdf_signature
+Exec=AppRun %U
+Icon=pdf_signature-icon
+Categories=Utility