ci: allow manual triggering of docker workflow

.github/workflows/docker.yml

@@ -1,6 +1,7 @@
 name: Build and Push Docker Image
 
 on:
+  workflow_dispatch:
   schedule:
     # run every night at midnight
     - cron: '0 0 * * *'
@@ -8,7 +9,7 @@ on:
 jobs:
   build-and-push:
     runs-on: ubuntu-latest
-    if: github.repository == 'Alexays/Waybar'
+    if: github.event_name != 'schedule' || github.repository == 'Alexays/Waybar'
     strategy:
       fail-fast: false # don't fail the other jobs if one of the images fails to build
       matrix: