New release workflow (#547)

* Port release workflow from Aftman to test

* Checkout submodules in plugin build step

* ...and build with submodules for other builds too

* Fix ci.yml; we use master branch still

* CI with submodules too

.github/workflows/ci.yml

@@ -3,11 +3,11 @@ name: CI
 on:
   push:
     branches:
-    - main
+    - master
 
   pull_request:
     branches:
-    - main
+    - master
 
 jobs:
   build:
@@ -20,6 +20,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
+      with:
+        submodules: true
 
     - name: Install Rust
       uses: actions-rs/toolchain@v1
@@ -40,6 +42,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
+      with:
+        submodules: true
 
     - name: Install Rust
       uses: actions-rs/toolchain@v1