Allow building a stand-alone appimage

adds makelove.toml and .gitignore
modifies readme to explain how to use makelove
adds a github workflow file to build appimages

.github/workflows/release.yml

@@ -0,0 +1,32 @@
+name: build
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-20.04
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        path: main
+        submodules: true
+    - name: Update
+      run: sudo apt-get update
+    - name: Install Dependencies
+      run: sudo apt-get install --assume-yes python3-pip
+    - name: Checkout makelove
+      uses: actions/checkout@v2
+      with:
+        repository: pfirsich/makelove
+        path: makelove
+    - name: Install makelove
+      run:
+        pip3 install ./makelove
+    - name: Build
+      run: cd main && makelove
+    - name: Release
+      env:
+        ARTIFACT_NAME_APPIMAGE: 'multiviewer-2.AppImage'
+      uses: softprops/action-gh-release@v1
+      if: startsWith(github.ref, 'refs/tags/')
+      with:
+        files: main/dist/appimage/${{ env.ARTIFACT_NAME_APPIMAGE }}

.gitignore

@@ -0,0 +1 @@
+dist/**

README.md

@@ -9,6 +9,12 @@ A rewrite of my [Defold Multiviewer](https://github.com/rgrams/multiviewer) in L
 ### Missing features from Defold version:
 * No native file dialogs (which only worked on Windows and MacOS anyway).
 
+### Build a stand-alone appImage
+
+We can use [makelove](https://github.com/pfirsich/makelove) to build a packaged image.
+
+Simply install makelove using `pip3 install makelove` and run `makelove` in the root directory of this project.
+
 ### Added features from Defold version:
 * No CPU cost at rest
 	- The window is only redrawn when you interact with it, so the CPU load should be pretty much zero when the program is just sitting there.

makelove.toml

@@ -0,0 +1,10 @@
+name = "multiviewer-2"
+default_targets = ["appimage"]
+build_directory = "dist"
+
+icon_file = "Multiviewer_icon.ico"
+
+love_files = [
+    "::git-ls-tree::",
+    "-*/.*",
+]